Jeffery,
I work for an open standards digital consortium. The Denon and Pioneer connections are proprietary solutions. The Denon solution is different from the DVD-A solution and will probably require at least a software change in both the receiver and DVD player to work with any DVD-A solution.
What I am saying is that people shouldn't worry about "future" solutions that have no end in sight. A digital solution for DVD-A is at least 2-3 years away...
Adding a currently useless Firewire connector will do nothing to enhance the 950. On the contrary, it would just slow the release down. Worry about Firewire when there is actually "stuff" that supports it. The 950 isn't being marketed as "upgradeable" and "futureproof". For that, currently, expect to pay $3000-4000 from other companies.
The 950 is the BEST bargain out there for what it has! Buy it! Don't worry, be happy!
-Kurt
P.S. I don't buy proprietary solutions, if I can help it. So Sony and Phillips can take SACD and shove it. I will not buy a player for it or the discs. IMHO, SACD is a poor solution for digital high fidelity anyway.