The spokes are user replaceable, and can be ordered through the LBS.Look around the forum and you'll find quite a bit of talk about them.
I can sum up a lot of what's been said in the following:
Low spoke count for your weight (I weigh roughly the same as you)
Proprietary spokes - pain the a&& to obtain and replace when needed - wheels have to be sent out - must buy a set from Shimano unless your lbs stocks them.
I have read about break track problems - just google this one to see
The positives are the hubs and skewers - most tend to agree on these points from what I have read.
I have no first hand experience with them - but did research these ones quite a bit when looking for new wheels - they were on a short list.
I think Shimano may be releasing new wheels @ the tour or some point son - you may want to hold off and see what is coming down the line.