I've just come across something rather interesting at rec.pro.audio, which I think bears repeating here.
Some of the newsgroup regulars were at the AES show. Apparently there were
four tape manufacturers exhibiting at AES. Alongside Quantegy, RMGI and, ATR it looks like Zonal have risen from the grave, at least to some degree.
They don't seem to have a website as such, but apparently this is them:
http://www.zonalmedia.co.uk/
..supposedly 'Moonshine' has arranged for a third-party manufacturer to produce tape according to the old Zonal formulas. Apparently only the 675 tape is currently available, in 1/4" and 1" configurations, but they are hoping to have their 700-series (456-compatible) tape available soon.
If anyone wants to see the original thread, it bears the unlikely name of 'Tascam announces
HD-P2 portable compact flash recorder'. See the replies by Scott Dorsey and Mike Rivers.