Graham,
I think the closest thing you’ll find to that is PS is the Web Gallery feature, but for anything very elaborate you are far better off using a dedicated application. The Web Gallery is, as the name suggests, oriented to creating photo presentations for a website although they could also be launched as a web page from a DVD.
Regards,
Daryl
Since you’re unlikely to make a slide show from all 12,000 photos, why not just keep Elements (which you are used to) for making your slide shows?
Nothing against progress, but why do you think CS3 will "manage" better?
"but why do you think CS3 will "manage" better"
I think the OP might have been referring to Bridge vs the PSE catalogue system?
When I first started using PSE, the catalogue took a bit of adjusting to, as previously I relied on Windows folders to organise my photos – but after using it for a while, I found it a great tool (although I guess it might become a bit unwieldy with a large number of files).
On switching to CS3, it’s taken me a while to get used to folders again – but to the OP I’d recommend making the change, there’s so many more things in CS3. And Bridge has more than enough labels/flags/keywords to be able to keep track of things.
Like John, I’d suggest keeping PSE for doing your slide shows.
