What OS are you running on the Poweredge 830?
What Internet browser do you use? I ask that because if it's IE, you will find some sites that don't support older versions and newer plug-ins such as Adobe reader won't work, yet you might be required to use them under certain circumstances. The problem with Microsoft and some of these "plug-ins" is they are forcing us to upgrade.
FWIW, I look after appx 50 workstations running WinXP in a Win Server 2008 domain environment. We are not running into any compatibility issues.... YET, but I know it won't be long.
My 5 cents worth ... keep what you got for as long as you can. As long as you have good firewall and anti virus, I would't be too concerned.
As for the hackers and virus creators, really... I doubt they are going to focus on WinXP users because that following is dwindling rapidly so where's the payoff? Besides, it's not the OS that's protecting you when you have a firewall and a good A/V.