To me, I think that the digitizer pen input is a must for work. The simple fact that the pen provides a thin/small point compared to your fingers, makes jumping to text locations easy. You can also insert with ease drawing, sketches and diagrams (and math). While possible with a keyboard and mouse it's definitely more time consuming by a long shot (unless you use Visio for your diagrams, but that is more for official final work to show, and not just express an idea on the go)
I have done extensive research, and I found massive flaws or potential issues in nearly all offering, except the ThinkPad Yoga (the one with the digitize pen), and the Surface Pro 2. Both are very good products.
The Surface 2 is also a great choice, but I see it more as for students in a non-science, non-medical, non-engineer class, where its nearly all typing. The power of OneNote and Office on your side on the device is great, and with Flash in IE11 it provides you with a great web experience that you won't be blocked with anything. You can edit and view PDF with Word, and you have the Reader app (let alone you can download Adobe Reader Windows 8 App).
The Surface Pro 2 strength is providing similar battery life as the ThinkPad Yoga, similar feature, but is more compact. It must be noted that, however, if you plan to use Windows desktop a lot, at native DPI setting (100%) to enjoy the full workspace of the provided 1080p display. You must have good eyes that see things small. Personally I have no issues, and I can see fine with a small distance, but i know many won't be able to. The yoga, being bigger and same resolution, makes that setup easier, as things will be larger. (there is a half way DPI settings if you wonder). Go at the store that has a Surface Pro and check it out.
It must be noted that the ThinkPad Yoga is using a PWM (Pulse Width Modulation) to control the back light level of the screen, instead of using a real dimming circuit (costs more to implement). PWM is generally used on budget monitors or mainstream monitors, as a cost effective way to provide the ability to control the back light level of the white LED back light. The way it works, is that it turns ON the LED's at full power, then turns them off, then turns it back on than off, continuously. The lower the brightness the slower the rate it goes, the higher the brightness the faster is goes. The flickering is not visible by us as it goes really fast, but many people are sensitive. Many cases of people having headaches when using a computer for a long time, or trouble reading text on the screen, is due that the monitor uses a PWM to control the back light. But usually, for most people, a PWM back light causes no problem, as either they are not effected by it, or they don't use the computer long enough to see a problem. So if you know your wife is sensitive to a PWM back light, the ThinkPad Yoga might be a problem. I can't comment on the IdeaPad Yoga 2, as I don't know.