I would like to see all of your eCommerce plugins (eg. Membership 2 Pro, MarketPress, etc) share a common set of payment gateways, perhaps adopting a similar approach to WooCommerce.
Membership 2 Pro is such an excellent plugin, that it's a shame it doesn't have the other gateways you already support in MarketPress — eg. eWay.
From a Multisite network perspective (which of course is where WPMU Dev really shines!), I think it's confusing to have MarketPress and Membership 2 Pro network-enabled, because a site admin might see [eWay] in the former plugin, then wonder where its options are in the latter.
Hope this is on your roadmap already?