Obviously Dash use them for mixing/InstantX, but are there any projects using or with plans to use masternodes in other ways?
Spreadcoin intends to use the concept of masternodes to provide decentralised applications and services. The first service to go live is based on PoBN (Proof of Bitcoin Node) where a Spreadcoin Servicenode owner would be paid 30% of SPR mining rewards in return for running a full bitcoin node.
Spreadcoin was originally a Darkcoin fork but the masternode part of the code has been totally rewritten to form the new servicenode concept.
Other services beyond providing support to the bitcoin network will follow including decentralised exchange.
+101
Dash is focusing very carefully on being a currency first and foremost.
That means that other uses of masternodes are being explored all over the place. Some projects are scams, some are stupid and some are very innovative.
Spreadcoin is making slow and steady progress towards its road map goals. So there is no cheerleader campaign aimed at pumping the price, just a focus on creating services people would want to use but in a decentralized way.