CB Jarrett Bush had two interceptions against Seattle, and dropped a 3rd pick near the end of the 3rd quarter. I don't have any stats for him, but he's certainly allowed some of the receivers he's covered to catch some passes. CB Patrick Dendy hasn't played terrible, although he hasn't made any interceptions or big plays. It's a good idea to give Bush a chance at nickel back to see if he truly is playing better than Dendy.
Bush isn't some player who had a fluke game against Seattle either. He played well enough as an undrafted free agent to survive until the final cut in Carolina last preseason, and he showed enough ability in early 2006 that the Packers felt comfortable releasing CB Ahmad Carroll after the disaster in Philadelphia. Hopefully Bush plays great and creates the good problem of having too many cornerbacks who deserve more playing time.