The support since PSP 8.70 only contains security patches like the open SSL patches we had lately. So i think they would rather drop support but Many people still have 2003 servers.
This might be the last year and i think that's more than reasonable but then again i don't work at Hp. As long as large customers demand 2003 support they tend to update the 2003 server line.
One other thing would be the hardware support for Windows 2003 on newer generation servers.
