From the summit of Cedar Butte the principal view is to the east. I have two overlapping images you can refer to: left view [288 KB] and right view [285 KB]. (Or just print this description and take it with you when you visit.) By the way, all this is good for the Rattlesnake Ledges, too, as the view there overlooks Cedar Butte, and in the same direction.
When you reach the summit of Cedar Butte (via the new trail) you are pointed nearly east, and the peak you probably notice first is West Defiance (Mailbox Peak) (center of the right view). Beyond it on the right is Mount Defiance. Closer in on the right is the foot of Mount Washington. It is bigger, higher, and much closer, but it is nearly hidden behind a screen of trees (and not shown on these views). Between these massifs is the valley of the South Fork of the Snoqualmie River. We'll come back here in a moment.
Behind and to the left of West Defiance is an unnamed ridge prominently scarred with a logging road, another ridge, and then the craggy and spectacular double-hump of Russian Butte. Too steep for trees, let alone the roads to log them, it has a pronounced reddish color, similar to Red Mountain just north of Snoqualmie Pass.
Below all this you can see I-90 climbing up the flank of the flat-topped Grouse Ridge. Occasionally you may see a large cloud of black smoke from south end of Grouse Ridge. Not to worry! that's the Fire Training Center.
Moving to the left (see the left view [288 KB]) you are looking up the broad valley of the Middle Fork of the Snoqualmie River. Across the mouth of that you see more of Grouse Ridge. Below that I-90 disappears into the trees at Edgewick Road exit; just to the left you can barely make out Truck Town.
Back at the skyline, continuing on from Russian Butte, there is another ridge, and then the steep-sided Mount Garfield. Behind it is the valley of the Taylor River. I think the next prominence, overlooking the Taylor River, is Dog Mountain, but this needs checking. Further to the left are, vaguely, Quartz Mountain and Bessemer Mountain; these are the backside of the mountains that from Seattle--or the Highway 18 interchange--can be seen to north of Mount Si. From here they are peering out from behind the nearer peak of Mount Green, which in turn is half-hidden behind Mount Teneriffe (not in the image), which merges with Mount Si (visible through the trees) to the north.
Little Si is just off the west end of Si. Fuller Mountain--the isolated butte that can be seen to the north from Little Si--is just out of sight from here.
Now let's go back to where I-90 heads into the narrow gap at the south end of Grouse Ridge. (See right view [285 KB].) This is Twin Falls. (In the old days of Highway 10 there was a rest stop there, where one could peer down at the Upper Falls. Now there's a hydroelectric dam there; if you watch carefully, you can see the top of the dam on the north side as you speed by.) Just above that there appears to be a large landslide slipping to the right (sorry, it's just a bright blur in the picture); that is the sand and gravel quarry at exit 38. Closer in and to the right, hard up against the foot of Mt. Washington, is another gash. This is the old gravel quarry at Ragnar, situated on the old Milwaukee Railroad grade (now the John Wayne Pioneer Trail). The old grade used to be visible as it swept toward Cedar Butte, but now the trees have grown over it. If you can see it through the trees, note that the lower elevations of Mount Washington between Ragnar and Cedar Butte are quite steep; I'll discuss why in the geology section.
If you can make out how Edgewick Road goes south from Truck Town to the point where it meets the access road going due east to Twin Falls State Park, you'll have a good idea of where the bridge over the South Fork is. The hamlet of Edgewick that was destroyed in the flood of the Boxley Blowout was just this side of that.
Grouse Ridge extends across the entire Middle Fork valley like a dam. This is a moraine, or deposit, left behind by a glacier. Only this is not a terminal moraine (i.e., a moraine left at the furthest advance) of a glacier coming out of the valley, such as we might expect having seen the glaciers on Mount Rainer, even though this valley is a classic U-shaped valley such as glaciers carve. This is actually a moraine left by the glacier that flowed several hundred miles from British Columbia (not in sight from here!). It is so flat because it is a delta moraine, that was deposited in a lake. In looking up the valley of the Middle Fork you are in a sense looking into the side of what once was a glacially impounded lake. (See geology for more details.)
This moraine dammed (and still does) the original course of the South Fork of the Snoqualmie River. There isn't a lake behind it because it all filled in (what's now Ollalie State Park, past exit 38), forcing the river out of its channel and into its current channel over a rock ledge at Twin Falls. And having carved a channel into the rock, it can't get out to wash away the little that remains of the dam. The same thing happened to the Cedar River: once it flowed towards North Bend and joined the Snoqualmie River, but the glacier forced it up onto a spur of rock, and through the gap southwest of Rattlesnake Lake. By the time the glacier receded, it was caught in a channel it couldn't get out of--until the Masonry Dam was built. And then it did try to cut a new channel back to the Snoqualmie Valley just behind Cedar Butte (see Boxley Blowout).
Views to the south are largely obscured by the trees, and better seen from the Ledges. (See the view from the Ledges.) The fleeting glimpses to be obtained to the south look out over the Cedar Embankment, where the terrain gently slopes toward the City of Seattle's Chester Morse Reservoir (formerly Cedar Lake) to the south-southeast, and the Masonry Dam, about a mile south-southwest. (There used to be a view of the dam, but the trees at the dam have hidden it.) The Embankment is the deposit of gravel and till that has filled the original channel of the Cedar River, much as happened on the South Fork of the Snoqualmie River.
From the viewpoint further down on the new trail you are, of course, looking at Rattlesnake Lake and the south end of Rattlesnake Mountain; the Ledges are not quite as impressive looking as they are in profile. Down below is the John Wayne Pioneer Trail, where you hiked in on, and to the right of that you can make out Christmas Lake. (From the Ledges you can also see Rainbow Lake, but that is at a slightly lower elevation and not visible from here.)
The best guide for identifying these views is Richard Pargeter's "The North Central Cascades" pictorial map.
Here's a link to some on-line pictures.