Business intelligence (BI) is a business management term, which refers to applications and technologies that are used to gather, provide access to, and analyze data and information about company operations. Business intelligence systems can help companies have a more comprehensive knowledge of the factors affecting their business, such as metrics on sales, production, internal operations, and they can help companies to make better business decisions. Business Intelligence should not be confused with competitive intelligence, which is a separate management concept.Wikipedia

Although the explanation from wikipedia is disputed, it gives us a fair idea of what BI actually is. I don't believe I could have explained it better.

Although the acceptance and understanding of the term has only just begun, it seems that BI version 2.0 is on it's way. At least, that's what The Register says in it's article on Next generation BI :

As such, BI is moving away from being an exclusive tool for power users, or "information producers", to empowering the "information consumers" in accessing, analysing, and sharing data.

I believe that, although the term BI doesn't cover it completely, it has brought a better and clearer understanding of how business and IT can be tighter integrated to us all. 10 Years ago, IT was not seen as a serious business for companies other than IT companies. BI has brought the realization to business people that you can use IT to improve business. And that's what business is all about. If you can do something more efficiently than before, you can generate more business, and therefore, more money.