A PC that can run Linux (and XP in vmware).
A Mac that can run Linux (with XP in vmware)...that can dual boot to OSX.
In your case, it doesn't seem like that much of a loss (and more of a gain), considering it would be for work and you aren't paying for it or any of the software that would end up needing to be purchased for it, and if anything goes wrong with the hardware in it, your employer would be picking up the tab to fix/replace it.
As long as it's a high end machine that can handle running what you have now, and OSX, it sounds like a pretty good deal. You will still be able to be productive in the OS of your choice, if you need to switch things around a bit to meet a deadline. If OSX is slowing you down, you can boot up Linux and work there, or XP in vmware like you do now.
As far as software is concerned, you wouldn't be limited to only Mac software in your case, since you would also still be able to use anything you currently do on Linux and XP. So software isn't really an issue as long as whatever you are doing is in some standardized format that has software that can access the data cross-platform.
Since it is work, it's also likely you wouldn't be responsible for any headaches with networking...that is likely to be someone else's responsibility to get working properly. Plus if it did end up being your responsibility, you got those mac-heads you will be working with that should be good for something...don't forget that.
But if it was swapping a pc that YOU own, for a mac, and using it at home and being responsible for any repairs/replacements...and the cost of software...I wouldn't do it. (lots of reasons already expressed by others)
Even in my case, where I would be swapping an 11 year old hunk of junk for a brand new Mac, I don't think I could do it. I have a sentimental attachment to this old snail. I don't think I could trade it for anything. I'd have to be allowed to keep it, even if I had to retire it permanently.