Basically this is a salary dump by the Hornets to gain more cap space. Lewis is slated to make over $23m next season, but he can be bought out for $13.7m (remaining). They have another draft pick now too (already had #1, #10, #34) so maybe they can use an asset to take on a Bulls role-player instead of signing a FA. Usually teams just sign FAs though.
The Wizards seem to be trying to get into the playoffs next season, sort of going the Bulls method of putting 'professionals' around their young PG. Okafor and Ariza are now with Nene as multi-year contracts they've brought in recently after the purge of knuckleheads.