Hi,
Would it be difficult to ship multiple themes by default, for example
"legacy" and "tango" (and perhaps "qt" and "metal" themes in the
future?); the default theme could be selected at build time and the
default default could be set to "tango" for win32 and win32 only.
Distributors could easily decide which themes they do ship and it would
be easy to switch the default default from "legacy" to "tango" with
$next_major_release for all platforms -- while still making it
available for legacy purposes.
(In a way, this maps relatively close to how Java's Swing "Look and
Feel" themes are handled.)