The usual caveats apply:
-Rewrite lifetime is still limited. If you use it as intended- floppy replacement, etc- it should be fine; using it as a boot device may last as long or longer than an HD, but people have had them die after using them for swap. Devices using Intel StrataFlash (if any do) are probably the worst off in this regard.
-It's only interoperable if you stick to the Esperanto that is the default FAT format, of course. No magic there, though someday all platforms are supposed to reach UDF 'nirvana.'
-Data integrity is a tossup. Likely very reliable compared to Zip, and can't be scratched like CD/DVD, but on the other hand, one bad static jolt could potentially kill it. Humid storage conditions could corrode the connector, while attempts you make to to protect it might, too. (Viz. chip-eating ESD foam.)
-'Standard' solid-state memory products may or may not be cheaper per-MB. These things are basically the equivalent of a CF card + CF reader in one package; CF and SD readers are now <=$9, though you may have to cross your fingers as far as compatibility. (Readers supporting a single media type should 'usually' work anywhere. Similar bad luck could no doubt be had among the various pendrive products available.)
Certainly well-suited as a Zip replacement (isn't anything?), but I wouldn't trade a MO drive in for one, just yet.
