It will probably depend on how well the wheel was built and your riding style. Think of the low spoke count as making it more likely you could run into problems. How much more it's impossible to say.
If you do end up needing to replace your wheel it should become pretty obvious that the wheel won't hold up pretty early on. Maybe try to work out a better warranty on the wheel or assurance from the shop that they'll take care of you well if the wheel isn't as strong as you need it to be.
Scott