libpurple/blist.c
 * I'm not sure I like the way the blist singleton is done.  Having to call purple_blist_get_list() for everything internally is cumbersome.  A static file level variable like the parent_class variable would be a lot easier to deal with.  However, it would have to be created explicitly once and only once, but that's not a big deal.
 * line 1622 fix indentation

libpurple/blist.h
 * line 66 and 69, put a void inplace where there are no arguments.

libpurple/group.c
 * line 230, purple_group_remove_node, should have a first parameter of the object itself, in this case the group.
 * purple_buddy_get_group should be in buddy.[ch]
 * purple_group_contact_updated and purple_group_add_contact should be hidden behind a signal and purple_blist_node_add_child respectfully.