Agreed with the responses after mine above;
yes - the OS is increasingly unimportant in one way, i.e. it is and will be far less of a buying consideration for Joe Punter (and for Joe Corporate Punter too if the enterprise can interface with web apps on phones to the same extent as they do with Windows Mobile currently).
*However*, the OS issue will come into play where it impacts or enables functionality or cost or size/weight. E.g., if there's a phone with an OS coming from a vendor who writes bloated, buggy, resource hogging, expensive software (We'll call them "Microsoft" for the purposes of this example) that causes my phone to be larger, hotter, suck battery life, not work very well, and cost more, then even if it can on the face of it run all the standard web-apps-on-phones, I would still prefer another phone with that lighter, smaller, cheaper, stable, more efficient OS (we'll call them "Symbian" or "Android" for this example) that can also run standard web-apps-on-phones.
yes-Android could be a complete pile of poo, we don't know yet. However, with the source, the community can disect it and make it better, and secondly, given it's Google writing it, and all those other folks behind it, I'd say odds are very much in favour of it actually being really rather good. I'm not going to slag it off *just* because it's becoming fashionable to be cynical about big, rich, increasingly powerful companies called Google. Microsoft for example get and deserve a good kicking from some quarters (though technically ignorant business executives only see the surface of their success) because all their software is utter s**t and as a company they are close to being morally bankrupt, not because they are rich, powerful and successful.
Anyway, all will become clear on Android soon. More competition is great, and I actually think increased fragmentation at one level spurs on the industry to create standards, usually. The best thing about the J2ME fragmentation disaster is to show the industry how bad it can get, and if there's an ounce of collective sense, prevent it from happening again.
No one can sensibly argue though that Symbian are not in a great position, and deservedly so, they've earnt it.