It is extremely important to exchange key team members of both the teams for a few weeks so that they understand each others team. Knowing each others name is not sufficient.
Technology and Communication: Somehow western programmers come with inherent ability to communicate effectively as compared to the offshore programmers. So, offshore vendors always spend extra effort to correct this weakness by pushing the senior and more experienced programmers to the front line to manage projects. So, it is difficult to find "programmers" with 10-15 years of experience in offshore teams, however you can easily find "managers". So, don't expect people at 10+ years sit and code as compared to the onsite counterparts. The subject of whether experienced offshore developers should code or not itself is a debatable subject, but let me keep it for another day :-)