Jade, I know this is as important to you as it is to me. I haven't contacted you yet about this, because I aren't sure myself. I'll dig into this after the 5.1 release, however.
On installation, I'm personally of the opinion that everything we can do to make OpenACS install a simple matter of .deb or .rpm packages would be a huge step, but given that I don't have the resources to make it happen, offering hosted solutions would be a viable solution for now.
Freshmeat and other forms of advertising are indeed important. We've also talked about getting on sourceforge in the past. We have a pretty active community, and making it to top 5/10/20 on sourceforge could very well drive some new interest in the platform. Heck, it might even motivate some of us to put in some extra effort to move one more nudge up the activity ranking.
/Lars