The above solution worked for me too, for iCal, without any real issues so far.
Ridiculous that Apple didn't just make that happen for Snow Leopard users by default since it would have been the simplest bit of programming ever - or even just give people the information they needed to do it themselves without having to trawl the web to find it.
As for contacts, the various solutions posted on the forums and the web didnt work for me and seemed like a lot of hassle to go through have contacts synced via Apple.
The easiest fix is to export all your contacts, then import them into something like google (I already had a gmail account), and then just use google to sync your contacts instead if icloud (via the sync with Google button in the address book settings). Its a bit sluggish to update, but it works well. You can then point your iphone, and other iOS devices to use google for contacts too.
Again, ludicrous that Apple didnt just sort this out, especially for loyal MobileMe paid subscribers like myself - but it's their loss - look what happened in my case - I switched to Google. And since I've done that I might as well switch my Calendar to google as well. And then I might as well just use gmail as my primary email instead of using my mobileme. And thus, their ridiculous policy over icloud has lost them a customer, and from reading these forums, I'm sure many others.
Not the smartest business decisoin, but the Apple business is now built on selling electronic gadgets to new users, not looking after long-term customers. They seem to be doing well at it so good luck to them, but my bet is slowly people will creep away to other platforms, it just depends if they can keep growing new customers at a faster rate - which looks likely for the forseeable future.