I recently dished out a few bucks to buy some of these swimbatis everybody has been talking about. I bought some 5.75" poor boys silly rabbits, and was a little curious if i should be using them this time of year. Im in michigan, so the water temps are at or just under 50 degrees. I was thinking about tying one on a seperate rod and throwing it mostly when i see a shallow fish, since there are a few in the shallows. What do you think...

I say go for it.  There are some conditions that are better than others but swimbaits will catch fish pretty much year round.