IPStream = VPDN/L2TP -- That is considered bitstream anywhere else in the world. From an ISP's perspective you see every PPP frame of the customer.
That's LLU step no. 1 in Australia, UK, and pretty much everywhere else in the world. In fact, if you go and read up on Australia's Telstra vs ISP's saga, you'll see that either Telkom learnt a lot from them, or they learnt a lot from Telkom. Telstra however does offer Bitstream/VPDN, on pretty much the same model as Telkom's IPConnect. It just doesn't suck.
LLU Step no. 2 is how the Americans did it via CLEC's/ILEC's (and lately the Brits). This is NOT bitstream. This is loop sharing/leasing. This is were the actual loop is connected to your own DSLAM, and backhauled or terminated via your own PPPoE concentrator at every exchange. The ISP simply pays the Telco for the maintenance of the copper.
There is a 1.5 step in between where an ISP deploys his own PPPoE concentrator at each exchange, but practically it's much simpler then at that point to also deploy a DSLAM and take over the loop. This is definately NOT bitstream.
So I'm not sure what you're referring to when you say "not exactly bitstream" because from my perspective, and those of many already Unbundled markets VPDN/L2TP = Bitstream access.
Refer:
http://www.comcom.govt.nz//Industry...ntFiles/Documents/UBA Service Description.pdf and many others
Bitstream access = PPP over L2TP, or as it's known in Cisco Terms - VPDN - (Virtual Private Dialup Networking)