As far as I can tell so far there is nothing new with Acrobat X about PDF as such. It is all about Flash, the portfolio intro that can contain PDF as we have known it.
I did look at this when Acrobat 9 came out but it requires that the people you send files to upgrade and i found this was not always the case. I have not come across any examples of portfolios other than Adobe samples.
Maybe my experience on the general web is misleading. There may be organisations with standards on the latest Adobe software where portfolios work well. But I don't see this Flash aspect as moving Acrobat on around the issues of text documents.
There was a project to rewrite PDF as "XML friendly" . MARS was renamed as PDFXML but recently nothing has happened. The Mars blog
was last updated in September 2008. Possibly there will be more information when Acrobat.com is fully updated. Buzzword can export as PDF or ePUB, the format for ebooks that reflows on smaller screens. Maybe there is a view about workflows that cover various ways of publishing text and flat graphics. But there is no evidence that PDF has any further to go that would relate to this.
What Developers Should Know About Acrobat X , according to Joel Gerachi
, includes a new Portfolio SDK so that Flash Professional Designers can use their existing skills to create “Visual Themes”. This presumably assumes you have a copy of Flash.
Meanwhile the Adobe classic themes around Postscript and PDF are now based on ISO standards. Maybe it is reasonable that Adobe no longer relates to this much in promotion. But there is still activity around hard copy and flat documents. As this is no longer worth promoting or developing from an Adobe perspective, it is worth exploring alternative software either at other price levels or from niche suppliers where there is still an interest.