They could panic and block it, but that would just be silly. Besides adding torrent abilities to the client would add to its memory usage and would just waste time.
it is a better solution it reduces the server load. and if you program it good it wont add to the memory usage. even WoW uses it so i dont think it is bad
Server-load? *ehrm* you have to have a very low-end server if (in the worst case) the server can't handle 32 simultanous downloads.
As for the torrent part, I think that'll be no soo clever an idea.
Lots of people are still using dial up and the like where every byte upstream counts.
Now taking the game and voice-chat into account the game could get unplayable quite fast.
As we would have only the game-server as a tracker and max 32 ppl on one.
An average map is about 5 to 8 MB big... You can do the math, depending on how many the map are lacking and how much the others would be required to upload.
Another point are the then required ports, just like with any other torrent...
Take a look around how many ppl are still having probs with only the one we now need.
MOTD... is also not very usable as this afaik will be displayed between the normal messages and is overlooked if one does not look for it.