D Will stays with the Nets if Howard goes there either this year through trade or as a free agent this summer.
If I was a betting person, which I'm not unless the stakes are tequila shots, D Will will be a Laker next year.
One thing is for sure. The only way the Nets are going to keep him is to make a concerted effort to improve the team. The Nets have to be one of the least talented teams in the league. Outside of the rookie Brooks, the 7 ft. Brook (who is more a power forward) and Humphries (a good role player), that team has NADA in term of talent.
They would have to do what the Knicks did and turn the whole roster over. Whether the allure of playing in Brooklyn (and Howard could also easily go to the Lakers) is anyone's guess. The only thing they have going for them is the Nets owner is willing to spend money and they're moving into a new arena.