[nakajima]

As a heavy user of twilio (I work at groupme.com, we're entirely text message based, and built entirely on twilio), I'll say that every time we've broached the topic of international SMS, they've always cautioned us that it's experimental, and so we've explicitly marked our product as such (USA only for now).

That's not to say that we don't want international bad, but we pretty much trust their judgement as to whether or not they say a product is ready or if it ain't. Twilio does good work, and they're amazingly responsive to developer requests/feedback.