If your wife is or will be eligible for an SSN, you should wait to file your tax return until after she receives it. You can apply for an extension of the tax deadline to October 15.
Be aware that while filing jointly and electing to treat your wife as a US person, you must report and pay tax on all her world-wide income, even income earned outside the US. (She may qualify for a deduction or credit if she pays tax on the same income in another country.) Although filing jointly usually results in less tax than filing separately, that is not always the case when your spouse is a non-resident alien.
If you want to file separately (married filing separately), you can do that now. You would need to use a fake SSN for your wife to get Turbotax to finalize your return, then print the return, use some white-out to cover the fake SSN and write "NRA" (non-resident alien) and file by mail. You could later file an amended return to change from MFS to MFJ and add your spouse with their SSN (and any income that needs to be added per the rules above.) You have 3 years to file an amended return.
The one thing I would not do is file a joint return now and apply for an ITIN. That will cause delays now, and more hassles when you need to replace the ITIN with an SSN.
