I wondered the same thing a while back. Despite the 'deprecated' warning, I used them in the lars-blogger package and they seem to be working OK.
http://cvs.openacs.org/cvs/openacs-4/packages/lars-blogger/tcl/test/blogger-api-procs.tcl?rev=1.3&view=auto
I have noticed some hard to track down bugs. For example, if you run all the automated tests for lars-blogger, blogger_get_recent_posts fails the first time, then works the second time. I am almost certain this is due to a bug in the -init_classes functionality, but I haven't been able to track it down yet.
