Dota 2 will, without a doubt, be out this year. Valve has said that much.
I eagerly await its official release, however. LoL is fun as ever, but is far too easy for my tastes, and many of the champions overlap with each other, which is a bit dull.
I was very interested in HoN back in the days of its closed beta. I thought that it was pretty cool they were making a Dota successor. Then I played for a while, and realized that my eyes can't handle the ungodly explosions of color that many teamfights devolve into. Not to mention, the entire game has such a sophomoric sense of humor. I was content with it to a point, until I started to see how cruel and mean S2 was, and that turned me off of it forever.
Now, after playing Dota 2, it's impossible for me to go back to Allstars. Warcraft 3 has not aged very well in my eyes, so Dota 2 remains my only hope. It has a lot of heart put into it with hero interactions and what not, a great deal of visual aids for the player, and is aesthetically pleasing, unlike HoN.
Plus, it's a Valve game. That helps too.