('bump' is used to artificially push the thread back to the top of the 'latest posts' list to gain it more attention)
Your other options include maintaining your info site (on the assumption that it has a strong link history and good rankings) and adding a a subdomain. eg newtopic.widgetinfo.com While its true that you have to do some new link building for a subdomain you can legitimately link to it left right and center from your existing site :)
This works best when there is some relationship between the old topic and I just re-read and saw that there isn't, but its worth thinking about :)
A subdomain is a viable way to handle your problem ... and yes, the PR will flow from your home page to the subdomain via links just as it would to any other internal page.
That said, there are advantages to a domain just for your product.
The sandbox is really not as bad as it used to be ... of course, that also depends on the competitiveness of your terms, but starting fresh does keep the integrity of your established, but unrelated site.