Good information. I'm not all that big on mobile technologies, and I had no idea Flash was a dying technology... Youtube videos are all streamed as FLV flash videos, so I thought that was here to stay...
I certainly don't want to break support for iOS, so I'll have to do some trial & error to make sure the app supports as many platforms as possible. Note that this really only affects Preview, which I don't think is all that critical - the rest of the app is a combination of HTML5, CSS, and JavaScript, all three of which are supported on almost every platform out there.
I have to admit, using the DroidX with WiFi and my Hulu Plus, I'm just having fun right now. Not to mention, it's a full Linux box in my pocket... I've already installed a terminal emulator, and an SSH server that allows me to log into the device from my laptop... but that's the Linux geek in me

Having this much insight into the device also helps me understand it - it's just that with the preview function, it really will depend on what browser they are using. I think I'll target the default browser mostly, but I'd like to know it will function on Firefox, Safari, Chrome, etc...
The rest of the app, aside from song preview, works just fine on all browsers on all devices I've tried. And that's really what it's all about - being able to submit requests, text messages, etc. My real concern right now is the ability to use UPnP to not require port forwarding in the router. Note by the way, Android supports UPnP natively and easily, eg, streaming video from my MythTV DVR from remote locations. If they can do it, certainly VDJ can do it. MythTV is all open source, so one way or another I'll figure it out... My MythTV box is behind the same NAT router as my laptop, and it can be accessed from my friend's house with seemingly no problems. So there's no reason my laptop (and anyone's laptop behind any NAT router) shouldn't be accessible from the outside as well.