Frolik, 23, came to the Blackhawks during the 2010-11 season after spending two and a half years with the Florida Panthers. He had 11 goals and 27 assists last year after scoring 21 goals in each of his first two years in the league. He also had two goals and three assists in seven playoff games in 2010-11. He'll help the Blackhawks offensively next year, particularly if he can return to being a 20-goal scorer.
Lepisto, 26, played in 70 games for the Coyotes and Blue Jackets in 2010-11, tallying a total of four goals and 12 assists. His signing could signal the end of the brief Blackhawks career of restricted free agent Chris Campoli, whose role Lepisto essentially fills, and at a lower price.
For more on the Chicago Blackhawks, check out Second City Hockey, which has plenty of analysis of the Frolik and Lepisto additions.