This probably has been discussed and is probably a very minor point, but
consider how many more years we want to be able to use the <single
digit>.<single digit> major release numbering.
Assuming 1 year between major releases (7.3.0 -> 7.4.0 = +- 1 year),
then we have 7.5-9.9 = 26 years = up until +- jul 2030. if we skip to
8.0 now, then we have up until 2023.
Also we have 1 more chance to skip major number: 8.x -> 9.0. Imagine
what features will there be in 9.0 that is ground-breaking enough.
Because after that, we don't have any more major number to jump into
without going into 2 digits.
I personally don't see the major number as a very magical thing. Look at
Linux for example. People still see 2.6 as very different/ahead compared
to 2.4...
--
dave