T-Mo still has an unlimited bberry EMAIL plan for international. They've started clamping down on data other than email. T-Mo can turn on/off the international email feature as needed.
AT&T has discontinued the international unlimited data plan (which was a great bargain if you could get on the one they sold to corporate customers: $70 unlimited global data), though I understand that certain customers may be able to get an unlimited international email plan. AT&T discontinued the unlimited data plan when they dropped the caps & changed the domestic data plans.
Beth, email alone doesn't take a lot of data, unless you open attachments. If you're not gone for long (a week or two a year), you may come out OK w/email. However, you need to disable/uniinstall other "push" stuff, like Facebook, mapping application, and some news services. Those will chew up bandwidth, fast.
A plus to the T-Mo BBerry service is that it can use voice UMA over wi-fi from international locations without chewing up minutes or roaming charges. You'd need something like Boingo's mobile service which is $8/month.
One other thing to consider: in many countries in Europe you can find companies that sell prepaid 3G data services that work for a few bucks a day. Need a SIM card (GSM) data device, but if you're staying in the same country for several days & using a lot of data, it's worth the time/expense.