Words with Friends has been updated to allow cross platform play with Facebook players, but only on the phone version for now. According to the changelog on the Android Market:
What's in this version:
This is a big update! You now have the ability to play with your friends on Facebook! Just link together your Facebook and Words accounts and you'll be able to see which of your friends also have the game and start playing with them instantly (Honeycomb users, Facebook features are coming soon).
We've also improved stability and fixed several additional bugs.
As always, we appreciate your feedback! And if you like the new update, please rate us 5 stars!
Bug fixes are always nice, and we all know that Words with Friends can use them. The lack of an update for Honeycomb is a bit concerning, but hopefully Zynga can get that taken care of soon. In the meantime, if you haven't completely moved to Google+, link up those accounts and get playing! Download link is after the break.