While the OL is expected to be even better than last year, losing Jamaal will be huge. Being able to count on his pass pro, vision, incredible ball security and tough running style was such a blessing for the offense in it's first year as they were still figuring things out. He was as close to the complete back for this offense as we will probably ever get. We may be able to piece some of those things together through a RBBC approach, but no single guy has proven he is sufficiently close to having those things.
I can't say WR because I don't think they were as much a liability last year as they are made out to be. And partly due to the above, I think they will show a huge improvement over last season. There will be much more of an effort to throw the ball downfield this year and it sounds like (*crossing my fingers*) there is much more of a chemistry being built this off season between QB & pass catchers. I guess we're in wait and see mode for both RBs and WRs, but I just feel that we may find out pretty quick this season how nice it was having Jamaal out there to grind out tough yards, keep drives alive and protect the football so consistently.