Not bad ideas. But how about a 'theme' for each release? Like pick a system and make it seriously good like that one time that Haze did for master system? Or like what you did for the SGI stuff a few months ago? Pick some of the older systems that do not have a good emu and just bash on that for a month. Dogpile it. Like the orig XBOX currently has very 'meh' emus out there. But if MAME had it out of the box it would bring in more people? I think some of the more popular stuff has been ignored for fear of the companies lashing out. But some of this stuff is getting on 20 years old at this point and MAME has nothing or something that has not been really touched in 10 years. For some very popular systems too... For some of those systems people are going to other emus because the MAME support for them is not there or acts very badly.
To add maybe setup a poll and have people vote on what the next 'theme' should be?