Basically I had like an hour long discussion with a co-worker about how our site should be coded and designed. The site is a new social network focusing on new advances in coding and design. It's had it's face for about 3 weeks now and the issue has been raised due to the fact we use transparent PNG images for the icons.
My co-worker says that we should simply develop for IE7 this including the other browsers such as Firefox and Safari, simply asking the user to upgrade to IE 7 is they are using below. He uses the example of MySpace and Facebook who he says are both non-compatible with IE6 to an extent. He also says that industry top dogs say that everyone should be building sites to be compatible with newer browsers, not older. Such as Apple Computers now uses semi-transparent PNGs on their site.
Myself think that IE6 is a major part of the web sharing 32.0% of web visits. Therefore this means there are still millions of people using IE6. Where as IE7 is at 21.2%. Therefore we should be developing for IE6 even if it does mean placing background colour to all transparent PNGs. Against his argument about MySpace and Facebook is that they are not the best social networking sites online. They are the most popular no doubt about it Alexa has proved that. However this doesn't mean they have the best features or website development. Places such as Virb are much better looking with 10 times better features. Such as Microsoft being the most popular but we all know definitely not the best.
So whats your thoughts, should we encourage the users to upgrade their browser or spend a couple extra days editing all the images.
You should develop for IE6 if the userbase is hight. However there is a rumour that IE7 is shipping out as a automatic update at the end of the month and it will not be an automatic install (if it has not been yet).
However IE6 will start to dwindle down pretty fast in the next year. This being IE7 being forced and IE8 is now in public beta.
The rule of thumb is that you stop supporting browsers 2x versions and below. Expect Microsoft to give IE8 a huge push when out of Beta.
So in a nutshell yes you should develop for IE6 as it holds a the market at the moment but expect that to drop this year.
I know of an office that still uses IE5. In my personal opinion, anybody using anything IE6 or lower (or not Firefox) deserves to see non-functional webpages. Unfortunately the designer in me says to make sure to make it compatible for all users who might visit.
I think for the next year or two IE 6 should also be tested and compatible with any website. PNgs with transparencies is just one thing, what about new aPNG? (animated PNGS like animated GIF's) now that will have no hack...unless you just jump to flash :P