All those teams were keeping budgets low and banking extra money in the seasons leading up to the lockout, so they could do exactly what they're doing now.
The big market teams, for the most part, don't have nearly as much flexibility under the cap, either, so they're limited in their ability to go after the big names. They have to go somewhere, so the smaller teams are able to grab them.
The Blackhawks shouldn't really be thrown in there, either, because they make OK money, but their owner is the biggest tightass in the league (even more than Jeremy Jacobs).