If the Republicans do wind up winning both, the Democrats can basically force them into 1 district after 2012. It will be interesting to see where thy put Bridgeport, given that without that city CT-4 becomes a Republican-leaning district.
As AndrewCT said, I don't see how they can split CT-04. It's basically the Connecticut Panhandle by the New York border along the LI Sound Shore. Moving Northward along the CT border instead of into Bridgeport probably wouldn't change the makeup of the two districts much. I suppose they could split off the more minority parts of Stamford and put them into a district with Bridgeport and into New Haven, but that would probably make CT-03 more competitive. Plus, CT usually doesn't split towns without good reason.
Unlike MA, CT does split towns to achieve exact population equality. For instance, Shelton is split between CD 3 and 4. County lines aren't particularly respected either, since CD 4 jumps the line to include Oxford, when Shelton could have been left intact and a small piece of Stratford used to get equality.