As you probably knew, Parallax is taking full responsibility for the SX's distribution, packaging, test/qualification and support functions immediatelly upon an agreement made with Ubicom, formely Scenix.
Altough Parallax is continuing the Ubicom qualification program to comply with the European Restriction of Hazardaous Substances (RoHS) regulations, because SX52B is a large die in a unique small package and no packaging company for the chip in its current size has been found, SX52 will be discontinued after 1 january 2006.
Because last order for the chip should be issued no longer than 25 december 2005 you're unable to use it for mass production if you intended to do so.
If you want just to play with SX52 then you can try this DIY programmer: **broken link removed**
For additional SX52 support you can ask Ken Gracey moderator of Parallax forum : **broken link removed**