It doesn't have updates
In fact some of SpywareGuard's strongest protection is indeed its Browser Hijacking Protection, which doesn't need any sort of definition updates.
The current real-time protection built into SpywareGuard 2.2 has been extended about as much as is possible - which unfortunately means a complete rewrite is in order to allow for future changes and updates. This is something I've been working on, but it hasn't been quick in coming.
This doesn't mean that the current real-time scanning is ineffective - rather that it should detect most variants of the items listed here: »www.javacoolsoftware.com/sglist.html (Note: This isn't a comprehensive listing, but it should list most of the major items.) This should include more recent variants of those items, even without database updates, but it won't detect some completely new items (i.e. completely new spyware/adware programs, as opposed to new versions of, say, "RapidBlaster"). That's the difference with the current release.
That said, again the most effective and useful protection for most users has probably been the Browser Hijacking Protection component (which alerts when various browser settings are changed in real-time), which doesn't require the database updates.
A new version of SpywareGuard, with some rather interesting new features, is in development. While I don't yet have a clue when it'll be ready for release, I can say that, regardless of how effective you personally consider the real-time scanning component, the current version of SpywareGuard provides some strong protection against Browser Hijacking - by alerting the user as soon as such activity is detected.
It isn't a catch-all or an end-all (nothing is), but it's meant to be an effective layer. The choice, as always, is left up to the user. I just give them that option (for free).