looks like it's not that bad for the minimum requirements. although it's the minimum requirements and certainly not the fully-enjoyable specs.

edit:

you can find here some official video card benchmarks ran by the idsoftware team but only for the latest nvidia/ati video cards :

john carmack:

it should be noted that all of the modern cards play the game very well, and benchmark scores should not be the be-all-end-all decision maker. scores will probably improve somewhat with future driver releases, and other factors like dual slots or dual power connectors can weigh against some of the high end cards.

[h]ard|ocp:

id software has done a great job of bringing doom 3 playability to the masses, probably including a larger portion of the gamers out there than has ever been done with a cutting edge gaming title.

edit:

as regard to your game input, it's definitely not a "requirement" but check out this doom 3 keyboard by ideazon zboard:

edit:

and about the next idsoftware game requirements :