Looks cool. I would like to see some comment from CFB to make sure we don't interfere with some unrevealed feature, but then, I'll add it to Solaris.
Other client developers checking in?
I absolutely cast my vote for using a standardized Reed Solomon NXT account number all beginning with N containing the characters 2-9, A-Z while dropping the use of 0 and O and 1 and I. Adding just an N in front to denote "NXT" is a half measure. I think we should go for bold branding and have the first three characters of every address always be "NXT" so non-users recognize it and eventually become converts. This would bring the total length to exactly 20 characters, which can be either four groups of five separated by dashes, or five groups of four. I personally prefer the latter.