Congratulations on your pregnancy! I'm a firm believer in co-sleeping so you go girl!
I co-slept with all 4 of mine. I don't think i'd kick your other baby out of the bed though....especially if your using the co-sleeper. I wouldn't want him thinking or knowing he was kicked out for another baby KWIM? If he just gets in bed and cuddles and sleeps I see no reason for him to have to sleep else where. If you insist on getting him out of your bed I'd try covering his crate at night. GL in whatever you decide.