Is there a modern day version of the U2 spy plane, or is this work now done by satellites?

The U2 is still used over tiny third world nations full of brown people because it can easily operate where there is total air supremacy.

The Predator and Reaper drones are also used.

The problem with satellites is their predictability, cloud cover or weather, and that they take 90 minutes for an orbit and each only go right over the same ground twice in a 23 hour and 56 minute (ie, sidereal day) period.