At the end of summer I'll be building a new DAW for the first time in about 8 years, and during those 8 years I have only updated SONAR with patches and added Google Chrome to my DAW.

I can think of one hazard of being out of date, I expect to get hit pretty hard monetarily as I deal with the x64 compatibility issues. I'm going to have to upgrade everything, I sure my Waves updates will not be cheap. I've set aside about $800 for SW upgrades, hopefully that is enough. 

All that said, it's a new DAW. The old one will be sitting there ready to use until the new one is all working, only my Frontier Dakota/Montana cards will move forward. So, if big problems crop up I'll just move the cards back to the old DAW and can keep going. 

Once it's all working, the old DAW will be left intact but will start a new life as a Media Server for our house - the current Media Server is a 12 YO PC maxed out at almost 100% CPU so it's time!

I only connect the DAW computer to the intertubes to download drivers, register stuff, do updates and download programs I need. Otherwise the ethernet cable gets yanked. Microsoft Security Essentials is supposedly low footprint enough to be running without interfering with anything. Even the Cake tech guys said that. Most of my internet security is through Add Ons in Firefox anyway so if FF is closed there is nothing there (except MSE) to slow anything down.