Wait For Haswell?

It appears that the new Haswell CPUs will be released in early June of this year. If I was getting a desktop, or even a laptop with a dedicated graphics card, I wouldn't care much. However, I'm in the market for an ultrabook, and I haven't found anything decent with dedicated graphics AND touchscreen.

I'm pretty close to buying a Lenovo Yoga 13" (256GB SSD). They've upped the processor to an i5-3337U instead of the previous i5-3317U, both with HD4000 graphics. However, I'm wondering if I should hold out 4 months for the next line of Haswell ULV with HD4600.

Is it worth waiting? Will 4 months make for a much better, longer-lasting laptop? I want my next purchase to last 5 years if possible.

Thoughts?

(PS Sorry if this topic has already been discussed)