Spectrasonics does not do mailing lists, AFAIK. It would be in keeping with their business practices that any mailings would be opt-in only, but I've not found any option to sign up for newsletters.
In fact, if you log into your account and look under "Latest Info", it's still showing 2.01c as the latest release. And the image for Omnisphere2 still says "Coming April 30". It appears they don't even bother keeping their website up-to-date.
The company could sure do a better job communicating with its customers.