Hello Jarret Fayer,
We would like to inform you Intel considers this a mature product therefore the support we offer is only through our web site, as an additional detail the PCI Express* slot on this motherboard is designed to support graphics cards so it will not work properly when using a drive on this slot since it will try to capture video instead:
I confirm that it's possible to boot from a PCIe SSD with the DX48BT2. However if the PCIe SSD uses a RAID controller it will need to be configured and formatted on a separate system because the PCIe SSD configuration utility won't be accessible by pressing the displayed shortcut key. The DX48BT2 own BIOS seem to intercept this call and enter BIOS setup instead.
Also, the PCIe SSD will need to be installed in slot #3 which runs off the southbridge at PCIe 1.1 x4 full-duplex (500 MB/s). Contrary to the X48 chipset datasheets, slot #2 which links to the MCH at PCIe 2.0 x16 does NOT properly support full-duplex on the DX48BT2 implementation and therefore cannot receive data on half the lines. In slot #2 the PCIe SSD won't show up in the BIOS and won't be detected by the OS even with the appropriate drivers. There's no BIOS option to decouple slot #2 from slot #1 in order to support full-duplex so it can only be used by a graphics card through SLI or CrossFireX at 8 GB/s.
I successfully boot my DX48BT2 with a Mushkin Scorpion Deluxe 240GB (Quad SandForce SF-2281 64GB SSDs in RAID 0 on an LSI SAS-2308 controller) and it consistently reads and write at the theoretical maximum of 500 MB/s which still beats any SSD used with the on-board SATA2 controller.