I have yet to hear from the MozillaMessaging people to announce EOL for Thunderbird 2.x.
since I see new TB 2.0.0.25pre nightly builds here:
http://ftp.mozilla.org/pub/mozilla.org/thunderbird/nightly/latest-mozilla1.8/
and I see no more new SM 1.x nightlies here:
http://ftp.mozilla.org/pub/mozilla.org/seamonkey/nightly/latest-mozilla1.8/
I guess you might be EOLing SM 1.x first before MozillaMessaging EOLs TB 2.x.
2010-03-03 17:46