Wow, it's been 3 months since I stopped using flash.
dpkg.log.3.gz:2010-09-14 11:24:35 purge flashplugin-nonfree 1:2.8.1 1:2.8.1
At the time, there were known, open security holes in flash, and Adobe had announced a fix date -- rather far in the future. It made a lot of sense to remove flash at least temporarily.
I never found a compelling reason to reinstall it. I've missed out on a small amount of content, and had to do a little more to get at other content. But it's been worth it to not need to worry about flash slowing pages to a crawl, being insecure, bypassing cookie management, and being generally nasty, proprietary software.
Between youtube's html5 beta and
Vimeo's easy link on every page to switch to html5, I have no trouble
seeing most videos. One annoyance is when someone embeds a video
somewhere using only the flash player, and also doesn't link to its page --
but I am seeing more youtube embeds being done with html5 recently.
Youtube is also still inconsistent with some videos not yet being
encoded in html5, and so I have to pull out youtube-dl occasionally to
download and watch something. On the audio side, links to sound files
are everywhere, and use of html5 <audio>
is also very common.
The only thing I ever miss is Super Mario Bros. Crossover. I look forward to the day when the only use of flash is to play such historical roms in MAME.
I've found get-flash-videos very helpful for sites youtube-dl doesn't cover.
I wish I didn't need youtube-dl anymore, but as you said, the HTML5 beta only works on videos youtube has gotten around to encoding in webm.