I picked up the Redbox a week ago. I haven't played D&D in forever (the last time was playing original D&D in ~1983). I wanted to see if 4e was something I would be interested in trying out. Here are my observations (for what they're worth):
1. I was very dissapointed that there weren't any real rules in the set. It did a fairly poor job (IMHO) of describing actually how the game mechanic worked. I ended up downloading the starter rules from the WotC website (from the 'Take D&D 4th Ed for a test run' link) which were much more helpful and descriptive of the game mechanics. Actually, the starter rules were more like what I thought would be in the Red Box when I bought it.
2. It was an interesting method for walking one through character creation. Though I agree with the complaints of awkwardness involved in wanting to change something/look something up. It was difficult to make decisions about my character without really knowing how the game mechanic worked yet (do I want a high CHA or WIS? Hard to tell yet).
3. 1st level wizards are significantly more powerful now then in original D&D. I remember my starting wizard with two spells (that he could use but once per day) and a handfull of darts that he used (to very poor effect) once his spells were depleted (which was almost immediately). Part of the challenge of playing a wizard was trying to keep them alive until you reached mid-levels when you became very powerful (almost broketastic!) Now my 1st level wizard can do all sorts of things (especially since he's human). It almost seems unbalanced.
4. Despite my complaints, the Red Box did do a pretty good job of introducing the game. I now have a much better idea as to whether I'm interested in pursuing buying the books, etc.
5. I am likely to buy the books and continue playing. So in that regard, mission accomplished from WotC's perspective.
6. I have been playing Star Wars Saga Edition for a few years now. The 4e mechanic is just different enough form the SWSE mechanic to be annoying (does diagonal move cost 1 or 2? I want to run now, do I get 4 x move in a straight line, or move +2? I want to spend a destiny point! Oh crap - wrong system!).
7. While I won't stop playing SWSE, it's nice to be playing a system that is currently active and supported by the publisher. There is so much more material available for D&D than for SWSE. It's also obvious that WotC has much more freedom and flexibility with this system than with SWSE where they had to keep Lucas & co. happy.
8. I like puppies - as long as they're cared for by someone else. (Not relevant, but I just thought I'd throw that in there!