I haven't received my N900 yet, so I haven't had a chance to play with it. In a couple of days I will travel to overseas and unsure how the N900 handles the data connection while roaming. More specifically do I have to be afraid that every little widget or skype or anything that would be "always-on" would stay on and me being slapped with a huge roaming charge? Is there a centralized setting that would cut all of those widgets off of 3G/GSM and only allow them if there is WIFI?

It will ask you in default mode if you want to use the data connection when the phone recognizes roaming.