"good chance it will be rewritten to have a similar GUI.."
I agree and think that Apple may change it a bit when Lion OX comes out. Not sure if they will phase out the Logic brand and incorporate into the Garageband brand.
Garageband has its plus if you are a general user, but professionals "may" not run with it with a name "Garageband Pro" or something similar. After all, would you put down on the credits. "Garageband"? Though "hip" in name and is Apple, could be seen as non-professional.
I did some pro stuff years back, and I do say the name "Garageband" sounds cool for the beginner musician, but if you were a "Garageband", then you were mediocre by pro standards and just bugged the neighbors when you practiced for "dreaming" of fame...
Though I think the "Garageband" name for the product is cleaver and appealing, to the professional where names can be important for marketing, maybe Apple should keep the "Logic" name for the Pros. But the market is smaller for the pros, so the "Garageband" image may make them more money, as Apple seems to be more focusing on lately..
Since I am no longer a professional musician (by choice), I will stick (as recommended) with Logic Express. I do not need the "bells and whistles" currently and will wait and see what comes out.
I do like ProTools and have 8Le, but as I get older, I am getting tired of learning another system and would rather concentrate on making music instead of technical stuff now-a-days. Though ProTools looks easier to learn (I came from many years with Cakewalk-Sonar), I think I will stick with Logic Express for now.