Intel's G45 chipset seems to be just what the digital world has been looking for. Not only does it have dual memory support (no, you can't use DDR2 and DDR3 at the same time, just like you couldn't use SIMM and DIMM together) the option of DDR2 or DDR3 makes the G45 a fantastic chipset.
The X4100 GPU, while lacking any real gaming functions, it does has a lot of hardware based encode and decode functions built into it. Furthermore, its new DVMT sharing manages memory much better than previous Intel chipsets, limiting the stress on the system memory and keeping more total memory for system tasks rather than just stripping off a chunk like NVIDIA or ATI IGPs do; this regardless of how much they actually need at the time.
Using the discrete system, we see that the G45 and P45 are equal in performance. The only major setback to the G45 is it lacks a balanced Crossfire setup; the 8/8 setup of the P45 running on the Northbridge will work faster than that of the 16/4 configuration. While the first GPU has 16 lanes to work with, the other only has four lanes and it has to not only go through the ICH10R, but also through the DMI bus that the SATA/PATA and other devices on the ICH10R are using, limiting bandwidth again.
We hope to re-visit this board and give it an overall rating on its overclocking potential when it makes it to full production status. Then and only then will we be able to give you a yes or no answer for your buying, but its features and layout are extremely promising. Let's hope all goes well on release day.