Blacky the Blackball (of Dark Dungeons and Darker Dungeons fame)has finished Darkest Dungeons, a mashup of D20 with early Rolemaster, trying to take the best features of each. Blacky has renamed the game from its working title of Darkest Dungeons to Blood, Guts & Glory. The default setting isn't a medieval D&D-like world, but "a post-apocalypse Elizabethan England populated by anthropomorphic animals". However, if that doesn't do anything for you there are guidelines for using the rules in a more standard fantasy setting.
According to Blacky...
* The system has the standard 6 ability scores and 20 levels from the SRD; but with classes and their skill costs and spell lists inspired by those in Rolemaster.
* The system for buying skills is inspired by the one in Rolemaster, but skill usage is standard SRD (d20+bonus vs variable DC) and skill bonuses are therefore scaled accordingly.
* The combat round sequence is taken from Dark/Darker Dungeons; with attacks, damage and healing being made in a manner inspired by Rolemaster (but scaled for use with a d20).
* The rules for spell casting are original for this game, but take their inspiration from both those in the SRD and those in Rolemaster.
* Character progression is mostly "have the go up a level at plot-relevant intervals", but there are optional rules in there for using experience points (and awarding them based on the acquisition of treasure).
You can download a free PDF of the game at Blacky's Gratis games website here. There will be a print version (sold at cost like the print versions of Dark Dungeons and Darker Dungeons, I believe) in the future -- after us PDF early adopters find all the missed typos and the like.
I've never been a fan of Rolemaster (too many tables) but I tolerated is "baby version" in MERPS, so I'm interested in seeing what Blacky has come up with. I've downloaded a copy, but haven't had time to really look at it.