I'm sure it's been asked for before. I'd love to see mikrotik routers share connection tracking tables for fully stateful failover and the ability to have groups of VRRP interfaces fail over together. These two things keep me deploying more expensive openbsd firewalls in places where I could get away with a pair of RB750s. (Yes, I know VRRP failovers can be scripted but I'd rather have something built-in to deal with it.)