The 250 users / $1 million revenue thing is a bit weird. Any tech company with more than 10 employees probably has upwards of $1 million/year in revenue. The salary bill alone will be pushing that quite quickly. There seems to be a huge disparity between 250 PCs and $1 million annual revenue. If you had 250 PCs with less than $1 million annual revenue you'd be paying each employee less than $4000 a year.
There are startups with 5-50 employees that have no revenue. I think the $1 million covers "established business", and 250 PCs covers "really well funded startup".
I suspect there are a number of businesses successfully using Express today who are going to have to pay up for MSDN / Professional licenses, assuming Express goes away.
That's why the license said "revenue" and not "profit", just to make sure you need to pay for it, even if your company play some weird tax tricks and has minimal or no profit each year.
