A single layer of graphite (which is called graphene) would have a higher surface area per unit weight than this MOF. However, try making three-dimensional porous structure out of it!
Actually, very high surface area materials already have a lot of important industrial uses. Your at-home water filters, for example, are function entirely on the basis of having a larger surface area to weight ratio. So, materials like these have immediate uses as water filters (and many many other things, such as storing natural gas in cars: http://www.youtube.com/watch?v=QaKSekjAnqY).
The record that is broken is an area/mass value. Specifically, 7100 meters squared per gram of material (NU-110).
Yes, too small! The smallest virus that I am aware of has a diameter of 20 nanometers. The pores of MOFs are typically only a few nanometers (which is huge when it comes to trapping gas molecules). However, some day we may be able to design MOFs with much larger pores, which will be really cool for biological applications.
Absolutely! Today, these MOFs are more expensive than activated carbon, but tomorrow who knows? Also, MOFs can potentially filter out things that activated carbon can't.
For those of you who are curious to know more about our MOF research at Northwestern University: http://www.youtube.com/watch?v=QaKSekjAnqY