Put me in the who cares category. I have thousands of pages in HTML 4 and as long as they still work in browsers, why worry about it?
Keep in mind that HTML5 defines lots of details of browser behavior; so it might be worth to keep checking your pages from time to time, so in case some browser implements something breaking from HTML5 you can fix the pages to not break on it.
Ok, it is a bit of an oldish topic, but I have been reading both the drafts for XHTML2 and (X)HTML5 for the past two months now. Going through them vigorously. And I would *hate* it if (X)HTML5 became the popular standard.
Despite how much you could hate it, it is already happenning. It's not surprising that the HTML5 spec's copyright belongs to "Apple Computer, Inc., Mozilla Foundation, and Opera Software ASA."
(X)HTML5 is simply a very bloated version of HTML4. It is too stringent and does not provide for any flexibility. As I read it it felt more like a law than a standard. I also think that some mechanisms in (X)HTML5 do not do a good job of separating style from content.
XHTML on the other hand has done a fine job of not overcomplicating things while still produce a standard that is both flexible and innovative.
Here I have to disagree, and I want to clarify this point because it's the very root from which all the HTML5 thing began (by then known as Web Applications 1.0). Your statement is true for most of the XHTML2 spec... until you reach the Forms part. There are "good" theoric reasons for using XForms, but no practical arguments to redefine web forms: authors are asked to learn an entire new language for something they have been doing without serious issues for years; and browser vendors were quite unwilling to entirely re-write their rendering engines just because the XHTML2 group felt like it. And, since the group completely ignored all the feedback from these groups, there is no "officially known" good reason for XForms. The WHATWG activity began as a response to this, aiming to define a web-forms spec that would replace the XForms part of XHTML. Why did they later decide to replace the entire language with their own bloated tag-soup is beyond my understanding :o.
But other than that, I can only hope that we will be able to use XHTML2 sooner than (X)HTML5. In the end it is a personal choice and it shouldn't matter, I just pray browser manufacturers will implement both equally fast and complete. My choice is XHTML2.
Hope as much as you want, but I'm afraid that this is, unfortunatelly, not likely to happen :(. HTML5 is the browser vendors' spec: it is written by browser vendors, for browser vendors, with mainly browser vendors in mind. The only reason the W3C has adopted it is because vendros told the consortium something like "we aren't going to do XHTML2, but we will do HTML5, so you either pretend to agree, or you will have no more credibility". It's a fact: browser vendors have a good deal of power: they have the final choice on whether to implement something or not. Now they are aware of that power, and they are tyranically using it to impose their viewpoint over the entire Internet. If there were a choice, mine would be XHTML2 as well; but I'm afraid the only choice will be to feed the browsers whatever they want to chew.
a good internet site i found on google about it: [xhtml.com...] seems like it is better to still use xhtml 1.0/1.1 or html 4.01 for a while
Of course, it's still to soon to use any of these new specs yet. But I'd like to warn you that the site you mention is both biased and outdated. It misses the main issue of XHTML2 (XForms arrogancy); and some of the drawbacks it mentions about HTML5 no longer apply (for example, the <font> tag is gone for good; as well as the pre-defined class names).
Honestly, when I started this thread, I had some hope with HTML5. With the process being as open as it was claimed to be, it would have just been a matter of time for the spec to become better than XHTML2. However, after participating in many discussions for the last two months, I have realized that this is just a facade, and feedback is only observed from the vendors viewpoint: if they like it, it gets into the spec; otherwise it doesn't.