Unfortunatly it doesn't seem to keep a queue of unfullfilled requests, so it won't deal well with being out of invites. That would seem to be an easy enhanceent to add, the alternative is to hit reload occasionally or launch an evil wget command. I was able to get an invite within 10 minutes, which I fed back into the service since I don't plan to use gmail.
Since I last ranted about gmail invites stupidity, my maildrop filter has caught about 100 mails, including some big threads on lists like nanog, arguing pro and con about this form of spam. At a guess, these arguments are happening on a great many mailing lists. I hope this website will either help reduce the amount of offtopic gmail traffic on mailing lists, or convince google that it's time to stop with the invite business already. Google, you've wasted enough of the techincal community's time and bandwidth. Shame!