There are other options available, including:
Mask Pro (
http://www.ononesoftware.com/detail.php?prodLine_id=4)
Knockout (
http://www.corel.com/servlet/Satellite/us/en/Product/1152105 061771#tabview=tab0)
In the meantime, just install if from the Content disc. Look in: English\Goodies\Adobe Photoshop CS4 Extended\Optional plug-ins
I don’t think you should have to pay $100 for a comparable plug-in if Extract does the job. The Mask panel, Color Range and Quick Select do not offer comparable replacements for the Extract tool. With channels, masks and some tweaking you can get similar results, but for hair and wispy edges, the extract filter could give you some useful results. It wasn’t perfect, but it’s a shame they pulled the plug and didn’t really offer a better alternative.
And where’s the pattern maker? That one was handy for certain tasks…