I think it is a smart move by AMD. They are releasing the hammer (yes, Opteron will be available by April 22nd). They just decided to delay the desktop version. Opteron get full capacity and attention. Remember, money is the key here, and the opterons will for sure give more money to AMD than the Athlon 64 per piece. Granted, volume is lower, but at a product introduction the capacity ramp up is crucial, and the less demanded opteron should allow AMD to fine tweak the production process in order to allow higher volumes for future demand.
Talking about money, they have invested in Barton, and releasing a product that eclipses Barton so close to it means that basically Barton would be DOA. AMD needs to recover some of the cost associated with the Barton development.
As far as being competitive, I think they are so far. It wouldn't be a smart move to stop socket A when it has reached its highest point.
The question mark here is how welll will the opteron being received.