SQL Server : How to make "Update Statistics" faster?
I would start by seeing if you have any statistics that aren't being used.  Unfortunately that isn't possible directly but you could start by looking at your indexes and seeing if any of them are worth getting rid of.  If you can eliminate some of your indexes and/or statistics that will improve your run time for the UPDATE STATISTICS.  You can find out which indexes are actually in use by looking at sys.dm_db_index_usage_stats.

Here are a couple of links I used for reference although you can do a quick google search and find dozens.


SQL SERVER – Identifying Statistics Used by Query 
SQL SERVER – 2008 – Find If Index is Being Used in Database


Also as a general suggestion if you partition your table using a "partitioned view" so you have "old data" and "new data" then you can schedule your statistcs updates separetly.  For example let's say you partition your data by year.  You run the daily UPDATE STATISTICS on just the current years partition.  If there are no updates on previous years data then you don't have to worry about statistics updates on those partitions at all.  If there are updates on previous years data you can either 


Let them update themselves using the auto update functionality or
Update them say once a week 
And/or update them during an off hour time.