Great. Here is a thread where this was discussed during prototype phase and we even had Streacom chiming in:viewtopic.php?f=23&t=66632
The original plans talked about previously were for a 250W PSU so obviously they've had to downrate a little maybe for reliability. Possibly to be able to support 115V regions maybe? I wouldn't be surprised if it will go someway higher safely.
As for the lack of the 6-pin PCI-E power connector, that may be a problem for many. Streacom's original info given in that thread was that it would be included which did surprise me a little. The thing with putting a 6-pin PCI-E connector on is that they don't just have to be able to power a 75W card which has the connector only as an afterthought but that someone somewhere is going to want to hook up a 150W card. If you put a 6-pin PCI-E connector on a PSU, you're inviting someone to put that kind of power draw on it. I see why they've left it off.
It still has 2 4-pin peripheral connectors so a 6-pin PCI-E adaptor remains possible. Within a heatsink case you will still have challenges of keeping everything cool so a 250W PSU will not be the limiting factor of system TDP.