In the past 5-6 years I have seen Business Intelligence (BI) getting very popular and powerful too. For those of you who are new to BI let me first explain in brief what BI is, the official definition according to Wikipedia is "Business intelligence (BI) refers to skills, technologies, applications and practices used to help a business acquire a better understanding of its commercial context. Business intelligence may also refer to the collected information itself."
Now you may think that this is some new cool technology but you will be surprise to hear that BI existed since late 1950s in one form or another.
BA are very integral part of creating BI, interacting with customer, identifying reports, analyzing data, this information can then be applied to the BI, it does not make sense to apply rules to data if you don’t understand the data.
There is one thing everyone needs to understand that BI are great for reading data, massaging data and applying decision and generally does all this very fast, but one thing they lack which is "thinking" (until they perfect artificial intelligence of course), for now BA will do the thinking.