I am resident of MN, I forgot to attach my w2 with all documents, it doesn't stop here I applied for my wife's ITIN by submitting W7 along with it. Its says on IRS website that I need to send tax return documents (if applying for ITIN) to Austin Texas not Fresno CA where I had actually sent the papers. So, what's the impact going to be?

Now you can not do anything. If IRS has any query they will contact you. Normally, your return will be processed even if you do not attach W-2.