Although there had been speculation that Chelsea's injury-prone right back Jose Bosingwa may have been on his way out of Stamford Bridge, the BBC is reporting that the optional fourth year of his deal will be picked up by the club, which means the defender will be remaining with the Blues until the summer of 2012 rather than being free to depart after the season ended. Bosingwa had been linked to a number of teams, including Serie A giants AC Milan, and Chelsea were in turn scouting out several promising fullbacks to serve as his replacement (most notably Ajax's Gregory van der Wiel), but ultimately it looks like a move away from London is going to be pushed back by at least a year.
Bosingwa, a Portuguese international, came over to the club from Porto in 2008 for £16M, and although he was extremely impressive in his first Premier League season, adding an extra dimension to the attack with his ability to bomb forward down the right, he picked up a bad knee injury in October 2009 that kept him out for a full year, and although he's not healthy again he's had trouble recapturing the scintillating form he showed under Felipe Scolari and Guus Hiddink.
I don't see much of a reason for Chelsea to keep him around unless they couldn't find a replacement for him quickly (as good as Branislav Ivanovic is, there needs to be an attacking right-back on the roster), so I'd guess that the Blues found themselves rebuffed on their initial approaches on van der Wiel and Davide Santon and picked up their option as insurance.
Speaking of Ivanovic, it sounds like his extension isn't quite as complete at we'd hoped. From that same article:
I want to stay and I hope it will be sorted out soon. We are talking about my new contract but we will see in the next couple of weeks. I don't want to say anything wrong. I hope things are going the right way. This is all I can say.
Sounds more guarded than I'd like, but I can't see anything getting in the way now that money seems to be settled (he's reportedly being paid £65,000 per week, a bargain for one of the league's better defenders and Chelsea's most consistent centre back).