2400+ dpi scanner support

[Mike Davison <davison cs utk edu>]

There are many new low-cost scanners available that support 2400+ dpi and do a 
fair job scanning slides/negatives. Has anyone here had any success using any 
of these scanners with Linux? 

The local store has an HP Scanjeet 4570c and a Microtek Scanmaker 4850. 
Neither seems to be supported by Sane. Any experience to the contrary? 

Thanks,
Mike