Wvdial in the latest cooking works fine, except that (a) using ppp0 appears to ruin eth0 for use and (b) without kernel modules like ppp-async and ppp-deflate, ppp connections are useless. I set up wvdial for a Rockwell cdc-acm usb modem.
I checked tazpanel, and there was no mention of the ppp kernel modules anywhere, probably an oversight.