Sorry if this has been asked, but will the Intel 6205 wireless card work on the X60s?

It will work if (1) you install a third party BIOS to remove the hardware whitelisting (bear in mind there is the potential of bricking your ThinkPad if you do this) but also (2) if your using a half-height mini PCIe card you'll need a half height to full height adapter card to install it - an example one is listed below.

Half Size to Full Mini PCI-E Card Convertor Adapter | eBay

Exactly as he said.

Just to add: if you're reluctant to spend $$ for the half-length adapter, one fellow in this forum DIY'ed his own by cutting down an expired credit card to the correct size.