I wouldn't be bothered except as mesh/prim size changes are due this summer one has to believe this plan is near the roll-out stage and not just an early beta.
As yet no one understands them (well they probably haven't been set in stone yet) but they have to do with scripts adding prim cost. Sounds as though possibly prim limits will be raised. Mesh counts as variable prim numbers which are never set but vary even as they are resized. The mesh variable prim number due to complexity we knew, but the scripts/resizing/linking priority/other things are a bit mind boggling and surfaced recently. What parts of this, if any, are applied to prims?* To sculpties?*
*LL has never said any of it applies to non-mesh, however it seems prudent to consider that idea as the scheme including just meshes only gives great advantages to sculpties in particular, which can have a costlier resource profile. It seems like the weight/cost plan might be more logical (but much more painful and likely to break tons of content) if applied across the board.
Current mesh cost computation uses these factors:
dynamic_multiplier = 2.0
static_multiplier = 1.0
per_prim_cost = 0.5
base_cost = 1.0
if there are any scripts or the object is physical, active_cost = dynamic_multiplier. Otherwise active_cost = static_multiplier.
Cost scaler is currently 1.0
Server weight(per prim) = cost_scalar * (active_cost * (per_prim_cost + base_cost / num_prims)