It's probably been there a while now, but I just noticed that the doc library for "Oracle's Siebel Business Analytics Applications Version 7.8" (now renamed Oracle BI Applications) is now available on OTN here - http://www.oracle.com/technology/documentation/bi_apps.html
There are PDF download links for "Analytics Applications Installation and Administration Guide (7.8.4)", Analytics Applications Upgrade Guide (Version 7.8.4)", "Customer-Centric Enterprise Warehouse Installation and Configuration Guide", and a "Bookshelf for Siebel Business Analytics Applications Version 7.8.3"