HTML5: The new HTML 5 Also means I'll have to set down and start learning about the new tags, features ...etc.
If there's one hype I wish would die (but know it won't), its HTML5. Basically, in an effort to give us more semantic tags to use (since XHTML died due to one browser not supporting real XHTML), they've pretty much reintroduced presentational tags and changed rules willy-nilly (oh wait, not willy-nilly, it was design by committee... A committee of browser vendors who long for the days of <embed> and <blink> tags!). And clients doing more work (including dealing with security) and making legal things that aren't legal in HTML4 like anchors wrapping block elements... which wouldn't bother 99% of web sites out there, since they're already doing stuff like that (.000006% of sites even bother validating anyway :/ ).
But, unless you're a front-end web developer, you don't need to worry about HTML5. I'm a front-end web developer, and I'm sitting here not worrying about it. Most people are throwing on the <!doctype html> and then adding canvas (great, more js for me to block), the redundant header, footer, and aside, and audio/vidio tags. You can otherwise still write HTML4 with it if you want. Or the seXy X version if you want. So far as I know, nothing breaks, which makes it an easy learning curve.
Sorry for the bitterness, but many of us in front-end are quite unhappy with most of the ideas coming along with HTML5... but we have the choice to not use them, so it's not so bad. Don't worry: HTML4 is not getting replaced by HTML5, just as Perl5 is not getting replaced by Perl6.