Currently, you'll want to use your CNET Watch List for that. You can click "Add to List" on any download page to add a product to your list, and such will be done automatically if you download the product unless you change your account preferences. You can then manage your list at http://www.cnet.com/watchlist and you will receive an email notification every time a new version is made available on CNET. Note, however, that the Watch List does not reflect the version you have or whether a new version is available.

I agree it would be nice, in some respects, to have that merged with TechTracker, letting users manually add products to the list for version tracking. The greatest hindrance is that the user would have to add each product, as well as the version, and manually update the list every time the user updates/adds/removes a program on his/her computer. Few would want to undertake that effort, and it would be buggy given that the product name and version number would have to be an exact match to what CNET uses, without typos. Thus, I doubt it's a highly desired feature or a high priority, but I wouldn't completely rule it out either.

Finally, I should note that TechTracker uses the CNET Downloads database of software, so nearly every product CNET offers should be detected. Unfortunately, if it's not detected, that likely means CNET does not currently offer it for download, so it cannot be tracked or added to your Watch List. Should the program's developer offer it on CNET in the future, though, TechTracker will automatically detect it.

Hope this helps,
John