At the moment, there are 2 options to get notified of new releases:
Option 1. Point an RSS aggregator at the NeatUpload News RSS feed on the home page. I think there are RSS to email gateway services out there but I've never used one so I can't make a recommendation.
Option 2. Visit the NeatUpload page on freshmeat.net and click the "Subscribe to new releases" link at the bottom of the page. You will need to setup an account with freshmeat.net for that to work, but that's pretty painless.
In both cases, you will only get notified of new stable releases not development snapshots. If you really want to track the latest development code, you're best bet is probably to use SVN to regularly get the latest code from source repository and compile it.
If the above doesn't meet your needs, let me know and I'll see what I can do.