Thanks to behindthenet, I compiled some of Alex Ovechkin's stats.
Contribution percentage is a measure of with what frequency a player has a point when he is on the ice for a goal (points divided by goals for). You can read more about it here, here, and here.
Ovechkin's zone starts are far from his normal rate and his on-ice shots for are down by about 2.5 per 60 minutes. Note the extremely low "true" shooting percentage (goals divided by shots plus missed shots). He was able to counteract two other seasons of low "true" shooting percentage with a massive amount of shots. This season, though, he's only on pace for 227 5-on-5 shots.
The power play is probably the biggest issue. After always threatening 20 power play goals a season, this year Ovechkin is on pace for less than four. That can't last.
It looks to me like if we tweak Ovechkin's percentages to his career levels--well, his personal 5-on-5 shooting percentage and his total power play goals--then he'd be around 28-30 goals and on pace for close to 50.
Further reading: Behind the Net (Ovechkin's usage), Behind the Net (Ovechkin's shooting), Puck Daddy.