Two things make sense here. Memory leaks and lots of RAM on the computer. I upgraded KDE to 4.3.4 through the ppa. Also, the computer I am testing with has 4Gb RAM, more RAM=more memory used. After all is said and done, I am looking at a consistent 750Mb at boot. Still a lot bigger than GNOME, but I think that is to be expected. I'm going to try the CE when it comes out, but I don't think I can use it daily. I've used GNOME so long that KDE feels kind of awkward and bulky. Then again, the Mintified version may be more nimble.
"Contrariwise", continued Tweedledee, "if it was so, it might be; and if it were so, it would be; but as it isn't, it ain't. That's logic."
Lewis Carroll, Through the Looking-Glass, Chapter 4