That sort of set the tone for the panel, in my estimation. In one corner were people excited about Canvas for its novelty, its openness (Web developer Alon Salant talked about learning how to design Webpages by using the "View Source" command, something you can't do with Flash), and its small footprint. In the other corner is Flash and its broad set of tools for design and animation. It's not that Canvas isn't technically capable -- there were some pretty neat demos shown, including one using the Flot library that can dynamically generated charts from numbers in HTML tables. But Nathan Germick, a Flash games developer, said that his team just wouldn't be able to do the sort of complex animation they need without a broad pool of code libraries available. The back and forth was actually among the best I've seen at SXSW this year: there was a lot of substantive debate without acrimony.
It is of course completely legitimate in the real world to make a programming choice based on tooling -- after all, your users don't care what language you write in; they care that you can get it done and get it done cheaply enough that they can afford it. But it did seem to me that a lot of Haase's arguments boiled down to "we have the tools for rapid application development, and they don't." That's an advantage that can't last forever. Someone will make the tools. Maybe it will be open source folks, whose quirks developers tolerate better than end users; maybe it will be Adobe, which, as Haase pointed out, makes its money tools, though he obviously didn't commit to any HTML 5 editing software anytime soon.
The other big problem for both camps, of course, is compatibility. Flash runs almost everywhere -- and, with the upcoming release of version 10.1, will run almost everywhere much more quickly. The glaring "almost" aspect, of course, is the iPhone and, soon, the iPad -- a small slice of the Web, to be sure, but a growing one, and one that developers are excited about. Meanwhile, Canvas and other HTML 5 elements aren't supported by IE, a browser that developers have for the most part abandoned themselves, but which is obviously far too widely used to simply be ignored. But HTML 5 support is coming in the upcoming IE 9. In a world where developers still have to deal with IE 6's quirks, it's not everything, but it could be a turning point.