Converters == Don't even touch it.
Calculated with an Intel guy dealing with Tualatin (the 0.13 micron P3), and it just didn't seem to make financially sense to build a converter. It ended up being cheaper to get a new mobo.
Not only has Tualatin got different Voltage requirements, it also uses some previously unused pins of the 370 available - also, it has different level of voltage signalling.
I'm not going to bore you with details, but - in essence - your 440BX board shouldn't be able to support Tualatin. Sorry mate.
Hope this helps somewhat.
AFAIK they are being shipped to OEM's - we can expect a Launch around July/August...