JDK 1.5 will reach its "End Of Service Life" in October, 2009. JDK 1.5 will be no more officially supported after this period. You can buy, however, commercial support even for the next 15 years - if you cannot migrate to JDK 1.6.
...there is no need to worry - in case you are still running on JDK 1.4 :-).
NEW MUC Airport Workshop: Migrating Java Client (Swing / Java FX) to Web Standards