A word of warning to all who consider trying out DOTA 2 when it comes out, this game has nothing to do with LoL as far as gameplay goes.
In HoN any hero, even a mage like Veigar or a healer like Soraka, can get fed and "out dps" carries - not just that, but in LoL every hero can scale very well and benefits greatly from items.
In Dota (and dota 2) support type of heroes are expected (and even demanded) to spend even over 80% of their gold income (which is VERY low) on wards, potions, teleport scrolls, other consumables - not just for themselves, but for all the carries/gankers that need to save up their own money.
You, as a support/initiator/pusher and even a ganker, are expected to give gold, limb and life to protect and serve your carry - who in turn will carry you to victory, assuming he knows what he is doing.
It is a specific and potentially infuriating experience, since (as a non-carry) you are literally less important - even a lesser life form - than your carry.
Hence the saying goes, LoL is for casuals (where everyone wants a "kinda equal" role/chance/importance in the team) while Dota is for a tad more dedicated crowd that do not mind doing 45 minutes of "slaving" to your carry in order to win.