It's unfortunate that the Wii shop didn't become integrated into the Wii U shop, similar to the way almost all DSiWare is on the 3DS shop and can still be purchased and re-downloaded even though the DSi shop closed. It has quite an extensive catalogue of classic games that would have been nice on Wii U, plus a few WiiWare gems.
As for me personally, I only have a few VC games that I got as freebies, and have them in other forms with exception of Ogre Battle for SNES. I think I have around 20 or so WiiWare, but the only one currently coming to mind that I may want to replay is Fluidity. I'll be sure to have those two downloaded, but I don't know if I'll care if I end up losing the rest of my digital lot.
I guess I'll still try and see if all my digital games will fit on my old 1 GB SD card. This is where the 40MB limit comes in handy, as I know I won't have any single large game hogging space.