Here's an update on the roadmap for Linq2Sql. The post is pretty much confirming that they're killing off the project.
A project we started recently, we had to make a choice of which ORM to use. Since Entity Framework wasn't still up to par (and in certain aspects probably still isn't), and the team had experience with Linq2Sql, we decided to use that. However, from day one, we made a conscientious choice of not leaking anything of L2S into our domain objects.
This meant that we didn't use the L2S objects, but in turn used our own POCO classes. Therefore the sole purpose of L2S was to map data from the DB, what the job of an ORM is. Recently, and before the announcement, we found a lot of shortcomings when working with L2S and aggregate roots (I won't get into the details since Steve is planning a series of posts on the subject and how to handle aggregate roots with the different existing ORM's). We've therefore decided to switch ORMs. The beauty of it is that because of the clear abstraction of L2S, it's going to be very easy to swap out L2S for another ORM.
Now that we have confirmation that L2S isn't going anywhere, if you have issues with the current version and were hoping to get them resolved in a future release, I guess you're out of luck. So the time comes to move on. If you've abstracted well, it shouldn't hurt that much.
Obviously if you don't have issues with L2S and no projections on needing new features, then stick to what you have. "If it ain't broken, don't fix it". But don't start any new projects with it. Even Microsoft don't recommend it anymore.