There is a very interesting article in the Telegraph about teams having something to play for. Those that don't have a measurable performance drop apparently. So good news for Sunderland, really.
Sunderland definitely do have something to play for whereas West Brom don't. I still expect West Brom to try and 'do' Sunderland though. It'll need full on cencentration for the full 90+ mins and it sounds like the midfield matchup could result in a red card (either way), so it's vital to keep your heads out there too.
They also state that Premiership positions are worth 1.1million quid, which seems more realistic than 3million quoted elsewhere.