It claims to do it, but it uses incorrect option - it should be '--enable-system-sqlite' instead of '--with-system-sqlite'.
I just checked, ./configure --help and in does indeed say --enable-system-sqlite Use system sqlite (located with pkgconfig) It looks like we should do --- mozilla-thunderbird-3.0.1-r1.ebuild.orig 2010-02-25 13:14:32.000000000 -0500 +++ mozilla-thunderbird-3.0.1-r1.ebuild 2010-02-25 13:14:51.000000000 -0500 @@ -146,7 +146,7 @@ mozconfig_annotate '' --with-user-appdir=.thunderbird mozconfig_annotate '' --with-system-nspr mozconfig_annotate '' --with-system-nss - mozconfig_annotate '' --with-system-sqlite + mozconfig_annotate '' --enable-system-sqlite mozconfig_annotate 'broken' --disable-crashreporter # Use enable features
System-sqlite is no longer the default, and controlled via useflag. Fixed in 3.0.3 which will be going stable.