Monitor Pass opened today. That will shave a couple minutes off a trip to the east side for many folks. Hwy 395 seems to have a few more tourists each day.
Caltrans has plowed to top of Tioga Pass from the east, but the west side is not plowed yet. I believe the road is still closed at the lower gate near the bottom of Lee Vining Canyon. Often the east side of Tioga Pass opens just before fishing opener, the last Saturday in April, to allow access to Ellery and Tioga Lakes.
EDIT: Highway 395 will be subject to closure at night during May near Topaz Lake. There will also be delays during the day. There may be increased traffic over Monitor Pass due to the closures. Info about the construction projects is here: http://www.dot.ca.gov/dist9/projects/highpoint/