Do you need Internet Explorer support?

WARNING: This blog entry was imported from my old blog on blogs.sun.com (which used different blogging software), so formatting and links may not be correct.

I recently went over the designer code in Creator and checked how much of
the CSS 2.1 spec it covers.
It intentionally doesn't address properties
that are nonvisual (such as the audio ones), or the ones for paged media
(not a priority for web apps), or properties that are interactive in
nature, such as cursor - these are not appropriate for
design time rendering. (The cursor for example is already is used to
indicate designer state, like whether the component under the cursor is resizable.)

With the above removals, the list of missing properties is pretty short.
(In fact, the list got much shorter when I updated from CSS 2 to CSS 2.1, since
CSS2.1

removed a number of properties and property values I was not supporting. Now I
no longer need to implement
cjk-ideographic | hiragana | katakana | hiragana-iroha | katakana-iroha for list-style-type to be compliant, for example.

There is however another set of properties I haven't implemented:

• max-height, min-height, max-width, min-width
  
• content, quotes, counter-increment, counter-reset
  
• empty-cells
  
• background-attachment (apparently implemented in IE but incorrectly)
  

What's special about these, and why aren't they implemented?
I didn't prioritize them because Internet Explorer
does not support them. Therefore, many users probably don't want to rely
on them given IE's still dominant market share.

So, today I have a question in my blog: If you develop a webapp using Creator,
do you limit yourself to CSS properties supported by IE? Or can you assume
that your users will use a standards compliant browser like
Firefox,
Safari or
Opera?
And if IE support is important, do you need any of the above CSS properties
in particular? Finally, I know there were some rumors/discussions a little while
ago about IE development having been resumed; is there any truth to that,
and have they said anything about plans for full CSS support?

By the way, on Friday I implemented the last five missing properties on
my list (other than the above IE-missing properties):
visibility (clip
was already implemented), font-variant,
text-transform, text-indent, and
font-family search lists. Now I've gotta
go and make sure all the property values are supported for these properties
too.