Should __future__ statements ever be phased out?

[Steve Holden]

"Paul Prescod" <paulp at ActiveState.com> wrote in message
news:mailman.985117645.6322.python-list at python.org...
> Hamish Lawson wrote:
[...]
>  2. Always have a version declaration or feature declaration at the top
> of Python programs.
>
> You already have the ability to implement 2 if you are paranoid. You can
> check sys.version_info in your code.
>
<Erid Idle>
Ooh, beginning to sound a bit like Perl here, dearie, know what i mean,
nudge nudge? Wink wink ... just a touch too, how shall I put this, earthy?
</Eric Idle>

Seriously: how about Python 2.1 to 2.0, and 2.0 to {1.6, 1.5.2} converters?
Is it sensible to try and engineer backwards compatibilty post facto? What
idioms translate backwards through the language's development?

Also I don't _really_ mean to belittle version control issues, which I know
are all too serious a part of engineering.

regards
 Steve