What Google Base lacks (and what you can do about it)
So Google Base offers a way to upload structured data (even in large numbers as bulk upload) and a way to search it from your browser. Whats really missing is a way for other people (i.e. everyone but google) to use the structured content. As I have argued before I believe that offering such a possibility is not in the interest of Google and hence I don't think they'll offer one - or that they will restrict it (for example by limiting the number of elements that can be accessed per day).
So, what can we do about it? Luckily the solution is very simple: post the bulk files that you upload to Google Base on you website and let others know about it; and while we're at it: do the same for the files that you upload to Google's sitemap (alright, they are already on your website, but only Google knows where) and Froogle.
How can other people know where to find these files? That's easy: if you use RSS and ATOM there are already established methods: the nice buttons and more importantly the "alternate" link in the header:
<link rel="alternate" type="application/rss+xml" title="RDF-File" href="http://website/rss.rdf">For all the other files we need an agreement which types to write there - but from a technical point of view thats trivial.
What do we gain by doing this? We level the playing field, we make it easier for people to use the structured data, to build applications on top of it and to challenge Google. Not that I don't like Google, but should Google ever get so much proprietory data that it would get difficult to challenge them, even they will rest and slow down the pace of innovation. I fear the proprietory data could be the next Windows.
Update: Danny Ayers has the same idea, although he puts it less negatively.