Generally, MS collects suggestions from support services, the ones
responsible for interacting with the various Microsoft community and use
that to determine future changes. When the product gets to the alpha phase
it becomes dog food (tested internally) and the features are generally
locked for that release. After the alpha phase, a wider circle of
individuals inside and outside Microsoft are asked to test a beta version of
the product. So if you want to influence product features, reporting issues
to support service or the newsgroups is a good start.
Though most of the questions answered in these newsgroups are by unpaid
volunteers, a number of the developers and support service staff are known
to lurk in these newsgroups. So issues do filter back to those that have the
say on what happens to the product. So if you have an issue with how
something works (or think the devs got something right), post to the
newsgroups,
John... Visio MVP