hotswap drives an i386/amd64?

[Carl Brewer <carl%bl.echidna.id.au@localhost>]

For a long time I've used ViPower IDE/USB2.0 hotswap drives to do 
backups for servers, but I now need to backup terabytes and IDE hd's are 
all only 500GB or so these days.

My local yumcha suppliers can't get me a ViPower usb2/SATA enclosure, 
and I want to stick with their form factor for the convenience of the 
client. Swap these two drives once a week - very easy for them and 'good 
enough' backups for their requirements.

I can get the same form factor enclosure that uses hotswap SATA, I know 
NetBSD 4.x doesn't support hotswapping SATA, but does/will 5.0?  If not, 
what else would work in a similar way with very simple hardware?

Thankyou

Carl