Lynchburg/Roanoke are competitive as always this year. Northside is primed for another C3 run as Mike said. Haven't seen any Salem film, but they have certainly had a very solid season just looking at scores, it's not every year you beat both Cave Spring and Patrick Henry.
LCA is better than usual this year. They'll compete for the region title in 3C.
The valley and Charlottesville area are very weak this year compared to years past. Spotswood is beating every team in the Valley District by 40 and they lost to Glass twice. Staunton and Wilson Memorial are decent but have zero competition in the Shenandoah.
Even Western is weak this year by their standards, though still solid overall. Charlottesville first year of a coaching change, and Albemarle has a ton of talent but just hasn't put it together yet (head-scratching loss to a very mid-tier Godwin team).
I'd expect Northside to cruise through the west in 3C. They have Spotswood's number in the playoffs and don't think LCA or Western will have anything for them.
4D south will be very interesting this year. Tons of solid squads that could win between Glass, GW, Salem, Halifax, etc. Assuming Handley will win the north, that'll be a tough region champ.