I've spent most evenings since then (bar the weekend) tweaking, fixing and updating. I now have an upgraded server, hosting it's own wireless access point, Exchange, and nearly all of the important services that the old server had.
Now I just need to get everyone set up with Exchange and ensure they're happy with it, figure out a backup mechanism for it, etc.
It's taken a fairly monumental effort, but I've got there, and I'm happy with the results :)
On a side note, I got into work and it was still fairly gloomy. I got back from work and it was gloomy. Winter - bah, humbug.