This is a bit beyond my tax knowledge...
BUT...I did find that you are required to REPORT such a gift using IRS form 3520...though I am NOT sure if you would be taxed on it...
From the IRS website:
"Who Must File
File Form 3520 if:
4. You are a U.S. person who, during the current tax year, received either:
a. More than $100,000 from a nonresident alien individual or a foreign estate (including foreign persons related to that nonresident alien individual or foreign estate) that you treated as gifts or bequests or
b. More than $11,642 from foreign corporations or foreign partnerships (including foreign persons related to such foreign corporations or foreign partnerships) that you treated as gifts.
Complete the identifying information on page 1 of the
form and Part IV. See the instructions for Part IV."
From the looks of the form, for Part IV, line 54, you would check yes (that you received a gift in excess of $100,000 from a foreign person), and then list the date of the bequest, describe the property (cash) and list the amount.
You should REALLY consult with a tax accountant who is familiar with foreign gifts to determine what, if any, your tax liability would be - or if you merely have to report the receipt of the gift.
Abezon - any ideas on this one?
-Christina
Edit: This only applies if your in-laws are NOT US citizens. If they are US citizens, then they can EACH give you and EACH give your wife $11,000 ($44,000 total) before they would have to pay a gift tax on any amount over $44,000. I am not sure, but I think that you would also have to report any amount over the $44,000... Abezon?