I'm a big advocate of the phrase, "Release Early, Release Often." I think it is by far the best way to keep or gain community interest in a project.
Of course, that simple phrase doesn't quite sum up what you actually must do - simply uploading a release and announcing it on your mailing list is unlikely to attract interest. For example, who knew about 
Lincity-NG 2.9beta in lieu of the 
intended Lincity-NG 3.0?
Lincity-NG is in a bit of a mini-crisis. A victim of the 
shutdown of the Berlios developer services, all the web material is in a bit of a mess. Its 
home page is now on 
fedorahosted.org but still links back to the defunct Berlios page. There are entries on 
Google Code and 
Github that are up to date with the source, as well as an imported 
Sourceforge project* which is the only place you can currently 
find the beta, however all are unofficial / back up for now.
(* Not to be confused with this redundant 
redundant project)
Another game project which suffered was Battles of Antargis. It has 
re-emerged on Github and development seems to have 
resumed with C++ replacing the Ruby bits which previously encumbered the game. For a web presence, you have to use the Internet archive for its 
old Berlios page or external sites e.g. the 
LGBD entry or on 
Libregamewiki.
|  | 
| Battles of Antargis | 
 | 
It's not just Berlios that throws a spanner in people's works. Sourceforge has setback the oft-setback 
Extreme Tux Racer by closing down their hosted apps. The main communication medium was phpBB but now it is completely gone. They did manage to get an updated 
0.6.0 release online before this, at least.
Since there doesn't appear to be any project communication channel for ETR, I have contacted them suggesting a FreeGameDev forum.
Speaking of FGD forums, there's plenty of activity amongst the projects there. 
Stunt Rally continues to gain more strings to its bow. 
Sci-fi hovercrafts! That ought to be interesting. Despite being one of the prettiest open source games and incredibly put together almost by one person, CryHam - well, not quite; it took 
VDrift's physics and 
Ogre3D's jazz - the project doesn't seem to get the attention it deserves. 
|  | 
| Sci-fi overcrafts now in Stunty Rally | 
You can browse the tracks online. Check out this 
fun looking track with pyramids and chasms galore.
Another project gaining momentum is 
OpenDungeons. It's had its ups and downs, but seems to have gotten its footing now with 
regular test releases and several active contributors. The new website is coming along, but more importantly so is the game as especially Yohann Ferreira aka Bertram (of 
Valyria Tear fame) has come in and steadied the ship. I look forward to seeing creatures like 
this golem trudging dark, damp and dangerous dungeon corridors.
Of course the reality of open source game development is that it is not an overnight job. It takes years of perseverance to realise the goals of many projects. Over the course of that time, occasionally the rug may get pulled from under you. You just have to be prepared to dust yourself off, get up, and keep going.
Or you could just 
call it quits.