Intel has gone ahead and updated the specifications for the US15W or Poulsbo as it was previously known, although we have to admit that we missed the fact that Intel has two other SKUs of the Poulsbo chipset, namely the US15L and UL11L.
The updates to the chipset has added support for up to 2GB of memory on one or two DIMMs for the US15W and US15L, but we didn't manage to find out if this is also the case of the UL11L. Intel has also added support for the MMC 4.1 specification in the SDIO/MMC controller.
There are still a wide range of unresolved issues with this chipset and that might be why we haven't seen any products using it in retail as yet. The list of errata's consists of 18 items ranging from USB, to audio, to PATA and SDIO issues, but Intel is working on fixes to most of these problems.
The difference between the US15W and the US15L seems to very minor, with the only difference being that Intel is going to offer the US15W for at least seven years, which isn't the case with the US15L. The two chipsets have the GPU clocked at 200MHz, supports hardware HD video decoding and an external display port. There's also support for an external PCIe graphics card if it would be deemed that the internal GPU just doesn't cut it. Both versions support 533 and 400MHz bus speed processors, two PCIe x1 devices and have a TDP of 2.3W.
The SL11L on the other hand doesn't support external graphics solutions and it seems to have a much more basic GPU running at a mere 100MHz. lacks support for hardware decoding of HD video and it's limited to a display resolution of 800x480 pixels. This chipset is also limited to 400MHz bus speed and it only supports one PCIe x1 device. On the upside, the TDP is a mere 1.6W.
You can find the PDF with a few additional details here