I'm sure a lot of folks use multisite installs with WordPress. The fact that it can do this is outstanding. WordPress' actions and filters are also amazing (if woefully documented), allowing you to alter your code using your functions.php to get wordpress to essentially do your bidding.
One thing that's missing, though, is hooks for multisite actions. For example, there's no hook before/after registering a new site. This place would be perfect for ensuring homogeneity among new site installs for certain features, templates, etc.
I'm sure everyone would find this very useful. Any reason why this isn't/can't be implemented?