Not sure where you're getting that from, but it strikes me as wildly inaccurate.

- Not run on XP? I think it's pretty safe to say it will run on XP.
- 6GB RAM is totally unnecessary, it's limited to 2GB max by the OS anyway. 2GB will do fine, but 4 will be better.
- DX10 is not mainstream enough for them to not enable the game to run in DX9.
- I think SH5 will run fine on a 8800/9800GT, medium settings @1280x960 or comparable widescreen resolution.