Is it illegal to play online poker in the United States now?
No, except for a few states. The UIGEA addressed deposit methods and financial institutions (banks) that allow gambling transactions, not the players. A US DOJ official said in a Congressional hearing it was not illegal for US players to play online. The new law makes it illegal for US banks to allow gambling related transactions so the actual legality of online poker has not changed for the player. While it is clear that online sports betting is definitely a federal crime nobody has been arrested for playing online poker. See state bans above for more details and possible felonies.