Prometric 73-410?

I've been studying up to take the 70-410 MS exam. Even on Microsoft's own site it states it's the 70-410. I go to register to take it and it says 73-410? Is this just some internal Prometric thing or did Microsoft recently upgrade 70-410 to 73-410 with different material? Anyone heard anything?
Comments
72 Academic
73 MS IT Academy
70 Standard test
The tests are all the same, only the pricing is different. I believe both 72 and 73 require a voucher or proof of school to purchase.