"Arms no longer lifted above head when sneaking with certain weapons." Hell yeah!
"Fixed issue where Minigun audio could get stuck/keep playing indefinitely when fired out of VATS." A lot of people will be glad this if fixed.
"Massive world optimizations in major areas for better stability/performance with multiple DLCs installed." Sounds great!
For the full changelist, see the http://bethblog.com/index.php/2011/07/05/new-update-screenshots-for-old-world-blues/.
