The other DAW I've been demoing for use on my laptop (because Sonar chokes this POS) has a virtual keyboard. Very useful for trying out patches without a controller. Just clicking on the synth/instrument GUI really isn't a good way to get an idea of how a patch sounds and you certainly can't poke out melodies that way. I thought at the time when I first discovered it how nice it would be to have something like that in Sonar and almost immediately they announced it.
If it works the same (but I'm assuming it will be better) it will be great for just tossing in simple runs and chords without going through the bother of setting up my little controller (which is only 25 keys anyway).