Humanscale Design Studio has created NeatCharge, a mostly-unseen wireless charging rig that can be retrofitted to existing furniture (within limitations, see below). It consists of a roughly 5" diameter plugged-in charger that you mount to the underside of a worksurface, via either adhesion or screws:

A sticker is then affixed directly above the charger on the top of the worksurface, serving as an aiming point.

The limitation is that the worksurface can only be a maximum of 1.18" thick, so those with beefier desk surfaces will be out of luck.

However, I could see this device opening up the market for independent furniture designer/builders to offer wireless charging functionality; they could offer more slab-like desktops, and simply router out a cavity in the underside to accommodate the charger. And for those who find the sticker tacky, no pun intended, its purely visual function could be replaced with a veneer inlay or other surface detail.

Something I especially appreciate is that Humanscale's designers have carefully thought through the installation process:

The NeatCharge costs $149.