Firstly, I've not been asleep...just on vacation with no web access (a temporary escape from this online world!) and am now back.
When I set up my online gift store it was partly an exercise in on-page optimsation. The site runs on Cafepress' API and therefore (since Cafepress sells millions of products) has the potential for having thousands upon thousands of pages. The site's navigation (not the primary nav!) changes with every search (since it shows latest searches) and so every page is very dynamic. It gets crawled by Google pretty frequently (I'll dig out the logs and post about it sometime).
But...I think I over-did the on-page optimisation and although I got indexed pretty quickly, I ended up in the supplemental results index, which of course wasn't great since these generally show up only if there aren't many relevant results in the main index. I made some changes to the page titles, H1s etc (generally removing over-use of keywords) and watched over some time. Gradually, more and more pages came out of the supplemental results...but this was over a few months.
I recently checked and found that none of the results were in the supplemental index...or so I thought... After a little digging, I found (as reported by searchengineland.com) Google has now dumped the supplemental results label as explained in this excerpt from their blog:
"Since 2006, we've completely overhauled the system that crawls and indexes supplemental results. The current system provides deeper and more continuous indexing. Additionally, we are indexing URLs with more parameters and are continuing to place fewer restrictions on the sites we crawl. As a result, Supplemental Results are fresher and more comprehensive than ever. We're also working towards showing more Supplemental Results by ensuring that every query is able to search the supplemental index, and expect to roll this out over the course of the summer.
The distinction between the main and the supplemental index is therefore continuing to narrow. Given all the progress that we've been able to make so far, and thinking ahead to future improvements, we've decided to stop labeling these URLs as "Supplemental Results." Of course, you will continue to benefit from Google's supplemental index being deeper and fresher."
I guess this is good news in general since it sounds like even though the supplemental index still exists, Google are moving more towards getting rid of it altogether.