The addition of custom celebrations this year has been a success, but there are some things that EA could add, and edit to make them better in NHL 12.
1) Slow down the player celebrating's speed: When you score and move around it looks like your player is getting a speed boost. Tone it down a bit. Most celebrations don't have a player that is going fast enough that he could do 14.2 around the rink.
2) The ability to choose(pre-mapping) in the Menu screen: Much like in the NFL2K series, allow us to choose which celebrations we want. This allows EA more flexibility in creating more(as of right now I don't know how they'd add more with making it Mortal Kombat combo style). And it also allows players from different realms of the celebration scale to pick which ones they prefer. Some players are the more realistic ones, while others would like the dive and Tiger Williams.
3) Player-specific celebrations: Much like Maddens "swagger" rating, have players with a celebration rating, this allows vs mode players to have more signature moments as well. A player like Ovechkin would have a high rating, but someone like say Brad Richards or Pavel Datsyuk wouldn't. If you score a goal with someone like Kovalchuk or Ovechkin, their pre-mapped celebrations cannot be edited, but would have all of their go-to ones for you to use.
4) Allow the non-scoring players to interact: This happens moreso in the EASHL, where you set up a beautiful play, and the guy who scores goes diving into the boards doing the swim moves and your stuck with an uncontrollable player just raising either hand skating in a circle. Allow the user who scored to either interact with the non scorers(Say skating into the causing a hug celebration which is a standard in the NHL) and also allow for the non-scores to do the same, not do their own celebrations, just skate upto the scorer.
Allowing this would enable celebrations like this :
http://www.youtube.com/watch?v=1d5FjXOGVeA (Eberle celebrates behind the net, teammates join him along the halfboards)
http://www.youtube.com/watch?v=8j2dkSOq8Vs (Ovechkin does his signature celebration, and teammates join him at center ice)
This also allows for more feeling and a sense of that team feeling if you score a big goal, say in OT :
http://www.youtube.com/watch?v=SiqnaAMR-7Y (Morrow scores and doesn't really get a chance to celebrate before teammates are jumping over him)
http://www.youtube.com/watch?v=NNC8-PTTee0 (Hossa celebrates by sliding on the knees while teammates clear the bench and mob him at the boards)