Came to US end-June on L1 and spouse on L2 (spouse stays intermittently in the US, so while I will have completed more than 183 days in 2007 continuously in the US - single state, but she will have less than 183 days - also she has no income in the US).

Given this,
a) can filing status be "Married - Filing Jointly" which enables additional deduction
b) for her W-7, what reason will be appropriate ("a" through "g"?)
c) will I need to submit 1040 or 1040 NR?

TIA

a) Yes, you can file Married Filing Jointly under First Year Choice, but that means you must pay taxes on ALL of your 2007 world-wide income, not just what you earned in the U.S. You WILL get a tax credit for income taxes paid to your home country.

b) Cannot access the form right now, but choose "spouse of resident alien.".

c) Form 1040, 1040A or 1040EZ, whichever applies.

Yes as AtantaTaxExpert said you can file as married filing jointly if you meet the 183 days requirement and it does not matter if your spouse meets the requirement or not. Then you both will be treated as residents for the complete year 2007 and will file as resident.

Noted!