I too agree that reviews are the way to go, as advertising tends to be quite pricey. But as long as LsF calls itself "Alpha" noone will review it. Reviews are usually written about full versions, and, even though LsF is fully functional, it is not yet the final version of S2. Another thing are previews though...
So the best way to go for the devs IMHO is to hook up with IGN/Gamespy shortly before the release of "S2 Full" and offer them information about the features which have not been published before in any form (including forums and so on). Exclusive stories is T3H SeX0rZ for media.
Coming from the Red Orchestra community, they did another thing which boosted it's fame (allbeit the step was largely critisized in the community...): They made an agreement upon paying Gamespy subscribers could download the newest releases 24 hours before they would be available for the rest of us. Even though I doubt that many subscribers dled it within this 24h (or that many subscribed extra to dl the release earlier, for that matter), the fact that it was prominently (text and picture) on the fileplanet main page for at least this one single day sure resulted in hundreds, if not thousands, of downloads which else would not have been made.
Still, not anyone who is going to dl it will be a "welcome addition to the community" (enough wreckers on demo servers already) , or even stay with the game, but the community would grow nevertheless.
BTW, wasn't this topic about servers?