I am a huge Burton fan, but I didn't like Alice in Wonderland that much - I liked it, but I usually like Burton movies way better. I have to say it wasn't really the ending that bothered me, but the entire movie :p.
I thought Johnny Depp was actually very weak in his role I've never said that before
. Maybe it's because the Mad Hatter... Didn't really add to the movie. To me it doesn't feel like he should've had such a big role in it.
I also thought that at many points the movie was slow and that there were quite a couple of redundant scenes (for instant, where the Red Queen is talking with Stayne and the Rabbit is stealing back the scroll - it took way too long in my opinion, and it didn't seem as important for it to be so long).
Also, I found that the Jabberwocky was a bit too easily slayed >_>
There were parts I really liked as well. I loved the CGI. It was brilliant - especially all the animals. I loved the Red Queen (I just can't not love HBC). And even though I thought the White Queen was... awkward and I don't like Anne Hathaway and I liked her even less in this role, I thought she as the Queen fitted very well in the movie.
I adored the music. And the directing, of course. I loved the darkness of the world, too. I loved Mia Wasikowska as Alice.
I loved Tweedledee and Tweedledum, though I do think it was a bit disturbing that they had the face Matt Lucas (Little Britain) as I find him rather freaky.