This is what Apple says:
i5 1.3Ghz (2.6 Turbo Boost)
i7 1.7Ghz (3.3 Turbo Boost)
Based off this:
http://en.wikipedia.org/wiki/Haswell_(microarchitecture)
They are respectively these processors:
i5-4250u
http://ark.intel.com/products/75028
i7-4650u
http://ark.intel.com/products/75114
Here you can see how they compare:
http://2.bp.blogspot.com/-40qpLeO6B...+i7-3687U+graphics+performance+comparison.jpg
Since the battery life on the new Air is great (overkill maybe?), i would have rather had a i7-4558U in it (2.6Ghz base clock and Iris 5100). With it we would get the same battery life as the current Air, but also a much faster processor and intergrated graphics card.
Such a shame, and the screen of the Air is a joke. All companies are going to offer high resolution screens...