Impact when changing instance count for asp.net web role in Azure

Question

I'm having no luck trying to find out how channging the instance count for an ASP.Net web role affects requests currently being processed.

Heres the scenario:

1. An ASP.Net site is deployed with 6 instances
2. Via the console I reduce the instancecount to 4

Is azure smart enough to not remove instances from the pool if it is currently progressing requests or does it just kill them mid request?

I've been through the azure doco, goolge and a number of emails to MS tech support none of which were able to answer this seemingly simple question. I know about the events that get triggered by a shutdown etc but that doesnt really help in web site scenario with a live person waiting for a request to their response.