I'm buying my van through my company, and I'm getting 130% " super depreciation" which I can right off against my books over the next few years. It's a tax incentive, I assume to get the economy moving.
If you are going to order a new van, then yes sell your current car now as it's value is high, and if you can cope in a cheap run around for the next year or so, then do that. What you will find though, that cheap runarounds aren't cheap anymore.
But if you are thinking about buying a van as a short term thing, you will be paying top dollar for something I feel will crash in value in the next year.