Well for client to client communication there must be a server somewhere. If you are asking if it will be possible to make a 2 player network game (Host/Join style) it will definitely be, as well as a single server/multiple client game.
I'm using Hawk Network Library that according to my experience is very reliable, stable and GPL so there should be no licensing problem (But hey a RakNet plugin is always possible in the future <img src="{SMILIES_PATH}/icon_razz.gif" alt=":P" title="Razz" />). I've already coded a kind of working socket wrapper, i'll post something as soon as it will be usable.
Mk