That being said, if you have previously taken the FEIE previously, and now choose not to take the FEIE (because by not taking it you lower your tax liability), this is considered an revocation of the election to take the FEIE.
When you choose to revoke the election, a statement needs to be attached to the return to indicate so.
On top of this, if you choose to revoke, you may not re-elect to take the FEIE for another 5 tax years following the year of the revocation.
http://www.irs.gov/businesses/small/...=97026,00.html
Revoking the FEIE is ideal if you are in a high tax jurisdiation (i.e. foreign effective tax rate on FEIE > US effective tax rate on FEIE), and have no plans to move to a low tax jurisdiction (Middle East, Hong Kong, Singapore, etc) in the forseeable 5 tax years.
At least in Switzerland, since different cantons apply different tax rates, it is generally not easy to determine a generic effective tax on the FEIE. Suffice to say, someone in Canton Geneva or Vaud will certainly pay more tax on the same income as compared to someone in Canton Schwyz or Zug. Just as a hypothetical example, someone in Vaud earning CHF 300,000 may want to revoke the FEIE, against someone in Schwyz who earns CHF 400,000 will not find it beneficial to revoke the FEIE. It is all in the effective tax rates.
Just out of my own curiosity, I did a check of the US effective tax rates on the FEIE which is $91,400 for tax year 2009:
Filing Single -
Tax on $91400 is $19,319, Effective Rate: 21.13%
Filing Married Filing Joint -
Tax on $91400 is $15,231, Effective Rate: 16.66%
Tax Tables: http://www.irs.gov/pub/irs-pdf/i1040tt.pdf
If you need more time beyond June 15, then file Form 4868 to extend it to October 15.