Not very informative but interesting nonetheless: http://news.cnet.com/8301-1023_3-57464545-93/adobe-web-standards-match-80-percent-of-flash-features/
Essentially this is nothing new. HTML5 can do a lot of what Flash does but that 20% is big, because they are the high end interactions and gaming features which is what Flash is intended to do anyway. As I tell my students, at this point in time, you need to know Flash and its going to be long time before its gone so get used to developing in it and clients requesting it/needing it. I also tell them to start learning javascript because eventually it will be the future but at this point HTML5 is too new and its going to a long transition between Flash and HTML5. Additionally, Adobe appears to be the lead developer for HTML5 so you will more than likely continue to buy your authoring tools from them. Also remember that Adobe Air allows one to publish Flash Apps on iPhone and iPad.