since this info was on page 89 of this thread
i'd thought i'd start a new thread where more people might see it.
if your TF300 still has build 22.214.171.124 you can root it using SparkyRoot
this worked like a charm on my TF300.
now that asus has posted the .17 firmware
.26 can be downgraded to .17 then rooted. using method 2 from here
or the one click method from here
you need the BLOB file from the .17 firmware zip from the asus support site.
after your rooted download Voodoo OTA RootKeeper from the market to backup root.
with that backup you can update to .26 OTA and restore root. if you apply the update from the zip you loose root.