We've recently confirmed the 370SBA as being a production model. It's a BX board that supports 66 and 100MHz operation (for future Celeron support), and though the Supermicro 370SBA page claims that 100MHz support isn't available yet, a quick look on the manual reveals otherwise. Both the board and the manual contain printed settings for 66/100MHz FSB options on jumper JP11, and of course, the overclocking tests of the 366 to 550 proved this point.
Now here's where it gets a little weird. Apparently, Intel has locked the bus ratio multipliers on all production models of the Celeron PPGA (this is nothing new, they've been doing it regularly starting with the earlier Pentium IIs). This means that, like all of Intel's recent CPUs, the multiplier is locked. According to our source however, bus frequency has not been fiddled with, so you should still be able to adjust the bus frequency from the base 66MHz. This means that god willing, you will be able to run your 400 at
- 400 MHz (6x66)
- 450 MHz (6x75)
- 500 MHz (6x83)
- 600 MHz (6x100)
- 618 MHz (6x103)
- 672 MHz (6x112)
- 798 MHz (6x133)
As stated before, the 370SBA is almost identical to the P6SBA, save the CPU contact (more on the apparent similarities later). The other significantly noticeable difference is the missing JB1-JB4 jumpers, which on the P6SBA, allow for a manually configurable bus ratio multiplier. Considering the fact that all of the PPGA chips shipping will be ratio-locked, it's not necessarily lost functionality.
For testing purposes, SuperMicro was kind enough to take the board in and add the jumper headers for the multiplier. Please note that doing so definitely isn't standard operating procedure, so please don't write in to them requesting such an operation. Considering the fact that all the production chips will be ratio-locked however, it would be a moot point either way.