One group that will benefit most by Obama's gambit are lawyers, specifically immigration attorneys, but many other specialties, too – tax, criminal, business, class-action litigation, international law, drug control law etc. They will reap untold fortunes, mostly from taxpayers, but also directly from illegals.
Illegals desperate to stay are particularly vulnerable at the hands of immigration attorneys. Immigration law has always had some gray area. But now, Obama just made it much, much worse.