Over a year ago, in the early months of Minecraft, support was not a problem at all. Getting into contact with Notch was quite easy to report any bugs or any account/payment issues you had. Starting a few months ago, this got much harder. Minecraft's growth was incredibly fast, and the amount of problems grew just as rapidly. Mojang had set up multiple e-mails to try and organize this better, but they were just swamped with messages as well. The Mojang crew is doing their best to deal with every one of these issues, but it is currently just toomuch. This has led Mojang to take a larger focus on a support, and changes are happening.
The largest change was that there is now an official place for posting all of your questions, ideas, praise, and problems! If you haven't been to it yet, you can find it at this link. Mojang is now using a system run by GetSatisfaction, which is mainly community-driven. Customers can 'upvote' anything which they agree with, making it more visible to the Mojang employees. People have reported many problems with GetSatisfaction itself not being a very good bug reporting system, but the engineers of GetSatisfaction are working hard on fixing this! Many people have said that something such as Mantis Bug Tracker would be better suited for bug reports, though with the GetSatisfaction changes incoming, there is no reason to switch so soon after starting with it.
GetSatisfaction is well suited for a smaller company such as Mojang, as it is community-driven. One of the major things about Minecraft is its community, and they just go hand in hand. Since the start, Notch has wanted to interact with the community as much as possible, and this is a step to keep that true in the future. This even expands on that, as the Mojang employees can now see what the most-wanted ideas are, answer the most frequently asked questions, and learn about the biggest bugs in the game, as well as giving their opinions on it all!
It does get quite messy sometimes, but Mojang is looking for the support of a few individuals in the community to be moderators who will merge duplicate posts, move things to the correct sections, and simply keep everything simple. Currently, there are two of these moderators, one of which being Matt Howe, and the other being me. I can assure you that more help is needed, so contact Daniel Kaplan if you are interested(be sure to include any experience you have with things similar to this!) in helping. In the future, things will be dealt with more smoothly and quickly, as Mojang will be expanding even more in the future.