Just to be sure, you probably won't have a problem. The freehub failures on these XT hubs was a fairly rare occurrence, just something that sucks, especially on a touring bike and especially because of the 14mm axle which literally threw a wrench into the works as it were.

It would probably be apparent that there is a problem if you know what to look for, and if it progresses like mine and the others who have had the same problem you almost certainly would have enough heads-up to fix it. Like I said, if you turn the cassette slowly and listen and feel for evenness in the freehub then you're good, but if you feel it catch, or become like a fixed-gear, or hear an irregular clicking I'd fix it asap (by that I really mean at your earliest convenience, but don't put it off too long) by getting a new freehub body.

For me it was very intermittent (maybe 4 times that I recall) over about 1000 miles, then more regularly (~10 times) like within 100 miles, then the freehub was suddenly completely toast. At that point it would be a fixed-gear for a couple pedal revolutions, then the cranks would spin freely without doing anything until I hit a bump which would knock the little broken pawl back into "place" when it would become a fixed-gear again...

You will almost certainly need to get the 14mm allen from an online vendor, which is why I suggest getting one and having it on hand just in case you need to service your hub. When I said shops might not have it I meant *any* shops, including bike shops. I called or went to almost every place in town (city of ~275,000) that had tools an no place had one, and the good LBS took about a half-hour or so to find it in some old toolbin in the back of the shop.