Change it Up:
Substitute mangoes or peaches (or a combination) for the nectarines.
Dress it Down:
This fresh salsa can get very juicy because of the juice in the tomatoes, nectarines, and strawberries. If you want to go less juicy, there are a couple of options. 1) You can simply drain the mixture after it has sat in the bowl for about 20 minutes. 2) Use a variety of tomatoes that is more firm (such as Roma). 3) Eliminate some or all of tomatoes.
If you don't want heat, eliminate the jalapenos.