This wont change your mind, but there are a few apps that you can throw any format video at. The downside is that you're limited to the internal storage and you have to manage it through iTunes (however, there is one that I have that will allow you to wirelessly manage your files).
I saw some of those and, while they would help, it's still a bitter pill to swallow.
I really just wish there was a tablet with the app quality and build quality of Apple devices but the openness and options of Android devices. Currently I'm forced to either work around Apple's simplicity/limitations or Android's mediocrity/obsolescence.
Sorry, I didnt have the ipad in front of me when I wrote the first post. The workhorse is AVPlayerHD, it can play just about anything we throw at it. I dont even bother with conversions. For car rides I just load up a bunch of movies that my son would watch and we're set. I only have the 16gb ipad 1, but opted for the 32 "the new ipad" for this reason alone.