I forgot to mention that we talked to IBM support. They recommend we restart the management module on the blade before rebooting the whole blade to see if that does it. Since the blade isn't broken (i guess) and the management module must be the means for it to communicate with, eventually, vCenter, that is a logical step to take.
It should be noted that we have updated firmware on this management module and the blades very recently... i think we are completely up to date.
EDIT/UPDATE: Restarting the VMware Management Agents allows us to VMotion again... maybe coincidentally we changed the vSwitch gateway to a different IP (we aren't 100% sure how that setting works, our consultant directed us there... time to go read). This workaround corrected the problem on the two blades that started having problems. I suppose this means we need to look for a VMware update to fix this or maybe the old gateway IP we had was truly wrong.
Link to restarting mgt agent on ESX or ESXi: