Adobe released an alpha version of Apollo, a rich-client platform based on a tightly integrated mix of Flash and web browser. The Flash part of Apollo builds on Flex2/Flash9/AS3/AVM2 bundle of acronyms and the web browser part comes from WebKit, which Apple is also using in Safari. The weight of the merger amounts to about 8MB of runtime code. With runtime installed, AIR applications (*.air) can be downloaded and run. It's similar to the way Java WebStart works: almost but not quite like regular applications.
Flash runtime footprint has always been rather small and so is WebKit so it's a good match. And Flash applications can be pretty small but I have a high respect for engineer's capacity to be sloppy and wasteful so monster-size Apollo apps is likely to be a norm. It will be interesting to see whether graphics-oriented nature of Flash developers will outpace over-architecturing nature of Java developers when it comes to bloated code.
The major issue I have with Apollo is this: it's too WebStart-like.
RUNTIME DEPLOYMENT: I haven't been able to locate any document outlining Apollo runtime deployment strategy. I don't see box-makers nor OS makers shipping Apollo runtime built-in without forcing Adobe to bleed a lot of money or years of lawyering so they are in the same muck as Sun is with Java and WebStart. Cross-platform advantage of both platforms is nullified by .NET's built-in advantage IMHO.
APP DEPLOYMENT: AIR app installation, as of this alpha, require a file download, double-click to launch, then three dialogs on Mac (haven't tried it on PC yet). It's IMHO unnecessarily complex and annoying. WebStart app installation is annoying too but to a lesser degree. .NET apps are regular executables so .NET has the advantage here.
MEMORY FOOTPRINT: Like Java and .NET apps, Flash app memory footprint is rather large, in tens of megabytes. While this is not a major issue for really useful rich client apps, it's a burden that will suppress popularity of simple (in terms of functionality and developer time investment) Apollo apps which are necessary if not essential to float an application platform like Apollo. But then both Java and .NET shares this problem so this is a non-factor from competition perspective.
I can go on but I'll stop here for a premature conclusion: Unless Adobe make some serious changes, Apollo will be relegated to same lackluster status as WebStart and a tool for building pretty-yet-rarely-used widgets. If all Adobe wants to do is grab some headlines and become a subject of empty speculations for a while, I am sure they wil accomplish that, until attention moves elsewhere. But if they want more, they will have to stress more on shipping Apollo as the next generation web browser, not a not-quite-visible tide carrying a flotilla of cute apps functionally indistinguishable from other apps.