Pretty sure the target release is sometime this month, but it's done when it's done and not because some arbitrary date has come. You could also download the Beta 1 release, which has the spellchecker turned on, and is really quite stable. Just be sure all your favorite extensions are supported, or give the nightly tester tools extension a try (it can disable the compatibility checks Firefox usually does). Or, if you would rather, you can check the MozillaZine extensions forum to find a copy of the development version of Spellbound, which adds the inline spellchecking to Firefox 1.x. Not quite as nice as what Firefox 2.0 will have, but certainly better than nothing. Since that functionality was rolled into Firefox, there's no further development on it however.
If you use Firefox already, you should be sure to install AdBlock Plus and AdBlock Filterset.G. That gets rid of probably better than 90% of all ads, and then you can create your own rules to get rid of the rest.