I liked your article ( a lot ) and it seems that you put a lot of effort into it.

My view of running totals is simple. It is a CLIENT-SIDE responsibility.

Although it may provide you with an alternative to deliver to the developers what they may want out of the DB

IMHO looping through an ordered result set in the client is by far more scalable and "faster" end-to-end from the User point of view.

Just my $0.02