This debate is very popular nowdays. But if I you are interested in getting all kind of oppinions it's probarbly better posting on some other forums also
On the other hand, it will mean no plugins need to be installed with HTML 5.
It's so hilarious how people that haven't got a clue about flash or HTML 5, read a few articles on the web, and then go round telling everyone they should be switching to HTML 5 and trash Flash...
Adobe and its products are embracing new web standards such as HTML5, including Flash Pro. Have you read about the all new Flash Professional CS6, yet? It has a really cool export to HTML5 feature that allows you to export all your flash assets for HTML5 projects using the Toolkit for CreateJS. Check these videos for more information:
Please let us know if you have any other queries at all.