"It'll be a change, but it's not like you're going to watch something different next year."

Rex Hoggard is at the Disney event and does some research on the grooves issue. Early conclusion? Too early to tell for the most part since manufacturers have been slow to ship conforming clubs to players.

The new rule applies to all clubs, but most players already play conforming grooves in their irons. The only adjustment for the lion’s share of Tour players will be in their wedges and most agree the impact will be negligible.

From fairway lies, tests indicate a Tour player gets 3 to 4 percent less spin with the conforming grooves, which are smaller than the old grooves and not as sharp along the edges. “You really can’t tell the difference,” said Heath Slocum, who put the new wedges in play at the Frys.com Open. “Maybe a foot of extra roll on the greens. I couldn’t tell any difference.”

From the rough, however, there is a tendency for the ball to roll up the clubface, creating a shot with less spin that comes out higher than players are used to.

“You’re going to see players go to wedges with less loft,” said Todd Anderson, the swing coach for Charles Howell III and Charles Warren. “A guy will go from 60 (degrees) to 56 (degrees) to control shots better.”
Touch shots from the first cut of rough are also a concern for some players.

“From 80 yards out of the rough it’s going to be tough to control,” said Warren, who is 144th in earnings and did not switch to the new grooves at Disney as he attempts to break into the top 125 and secure his ’10 Tour card.

David Dusek offers this analogy from Davis Love:

But anyway, it'll be a change, but it's not like you're going to watch something different next year. It's like watching Talladega with a tiny bit smaller restrictor plate. To us fans it looked like the same race. It was just a little bit slower, but it looked like the same race. 
It's going to look like the same race next year. You just might see one ball roll a little bit farther on a chip and it'll just be because a guy played a different shot.