[quote=cahunter]If we buy under both’s name, we will get nothing. If my wife can get something, that is better than nothing.[/quote]

Depending on your income level and deductions it is possible to come out welDeductions become more limited, phase-outs apply at lower income levels, etc.
I would not be surprised if you end up paying back a major chunk of the 4k due to filing separately.

When making your decision to buy, I would ignore the $4k credit. Then when you do your taxes next year figure out whether you can make it work by filing separately. Based on the info above it does not appear to matter how you structure your purchase.