I just called them last Tuesday (5/20/2003) and ordered the 150W psu as well. I did not receive any email or confirmation on the order. I finally called today (5/27/2003) and asked why there was no activity on my card or email notification. I was told that the card would not be charged until the PSU is about to be shipped. Also told worst case the PSU would ship out on 5/29.
I have a feeling they are low on stock and are just getting the supplies back in, yours will probably ship soon.