Hi Steelfrog,
This time of year I camp at Upper Pines (both unreserved and reserved) or Camp 4 (unreserved / walkin). The Valley Floor is currently covered with snow. Upper Pines is nice because you can park your car at your campsite and easily unload your winter gear, fire wood, etc. But Camp 4 is closer to the Yosemite Lodge where I like to eat.
Upper Yosemite Falls is normally a nice half day hike. Currently I would take hiking poles and possibly some traction device. When you get near the top and it levels out you might need to struggle through some deeper snow for a short distance. Don't slip on the way down!
Also, visitors to the Valley Floor are currently required to carry chains in their car.
What a great time if the year to visit Yosemite!
Jim