Thinking of buying a DS for Pokemon...a question.

How does the online for the new Pokemon game work?  Does it limit your level or anything?  Or is it your level vs thier level. 

Also, is it like the other DS online games where its random who you fight?  Thanks!

You have 6 choices Free(as you put it, your lvl their lvl) Single or doubles, Lvl 50 sgl, dbl or Lvl 100 sgl, dbl.

It basically allows you to do this:
Battle people online
Talk to people online (you cant type-well you can but only words that they put in, and most of them are stupid one word at a time things)
Talk with the voice headset (only chat worthwhile)
Play the 'underground' flag minigame
make poffins with other people (a poffin is like a cookie to raise a pokemons coolness, beauty, smarts and 2 other things)
Trade people online

And thats all i know. I dont know if all this applies for goin on nintendo wifi as well, but this is for the ds to ds multiplayer. Hope i helped.