RE: [css-variables] ...let's change the syntax

After careful review of the following message, I think I get the motivation
for this change a lot more than changing the syntax for variables.
http://lists.w3.org/Archives/Public/www-style/2014Mar/0467.html

Would it be worth instead of dropping the "--" prefix when in "var()" scope
dropping the use of "var()" when and where the parser could cope?

So for example, the following would be an issue
  height: --profile-image-heightpx;
So var would be used:
  height: var(--profile-image-height)px;

However this would be fine:
  color: --profile-heading-color;

This would give a similar feel to variable interpolation in many other
languages and template engines - it may also break the boundaries more of
users thinking it's main use is for variables.

(Resending this as it didn't appear to go through the first time - sorry if
there is a duplicate here)