Hello,
As for the DIR-615, it should, but it doesn't...At least, the E3/E4 revisions I had. I contacted D-LINK support and was able to get a beta build that seems promising. But DHCP-PD over PPPoE works relatively well, minus a couple of little "features". I am hoping to have that hammered out soon, as the 615 is a capable little sub-50$ home CPE. But D-Link engineering seems receptive to my observations.
I have to check the state of the firewalling in it too 
Chris
My concern as an ISP is the fact that we provide our own CPE, but customers often buy off shelf CPE. This will lead to serious interoperability issues if the whole market doesn't get their act together.
Jack
There's a fine line we're trying to hold with what we support. We want to
establish a recommended list of residential grade routers for our customers
(where appropriate), that they can purchase themselves off the shelf,
without having to deal with the inevitable "you sold me this router, so you
need to make it work with my Wii and I don't feel that I should have to pay
you" type of headaches, if we were to actually sell the routers ourselves.
That rules out 3rd party firmware like dd-wrt, since the customer is
unlikely to get support when calling the vendor.
At this point, I'd be happy with two good options (two different vendors)
to recommend. So far, D-link is looking good.
Yeah, don't get me wrong. In most of our network, our CPE is bridging only. Customers wanted wireless and a few of the telco's were adamant about including it in their CPE (so the customer didn't have to go buy a wireless router from walmart). 90% or more of those wireless CPEs are still fully bridged (even the wireless is bridged to the wan).
I've tried my hardest to keep things where IPv6 from our side will just work. What a customer buys is their concern, but we still have the danger of gear which just won't be interoperable with our setup.
Jack
We've sold routers for years, but make it clear to our customer that we are
doing this as a convenience to the customer and that we are not responsible
for it.
It's worked for hardware failure, and since we end up providing initial
support for home wireless routers, having a model we're familiar with makes
it easier.
Frank
I agree with you, but I also know my telco's. It would go horribly wrong. 
Jack