title: Is valid HTML5 OK to use now?
body: <p>I've been reading about HTML5 and would like to start using some of it, particularly datasets as I've found an interesting looking jQuery plugin that I can start using...</p>
  
  <p><a href="http://www.barklund.org/blog/2009/08/28/html-5-datasets/" rel="noreferrer">http://www.barklund.org/blog/2009/08/28/html-5-datasets/</a></p>
  
  <p>Now, I understand that older browsers like IE6 may not like having extra attributes in there and may not know what to do with them but if they ignore them and the site still validates using an HTML5 validator then that should be OK, no?</p>
  
  <p>I especially want to make sure I'm not going to get penalised by Google etc. for not having valid markup and that I'm not going to get complaints from clients that their site is "not valid" when they check it using a bog standard W3C validator.</p>
  
  <p>What are people's thoughts on this?</p>