The real reason for HANA
Yes - HANA does real-time analytics - bring data from many sources and structures (including text, machine streams) and do real-time processing in one store on it. BW on HANA, HANA + Hadoop (check out new smart data acess) are use cases for it. Its a good place for many customers to start with a HANA project, delivers solid improvements on performance (+ HANA is amazing on the latest Ivy bridge 3x higher performance than Westmere).
However, the real reason for HANA is enabling the real-time business by erasing the OLTP+OLAP divide - somebody has to over reach to shake the industry, and it wont be the database incumbants who are gettign disrupted. With HANA you can analyze data as it is being captured (fresh vs old batch data), at interactive speed (i.e.google the data and follow your thought process), do deep simulations (e.g. MRP, often in DB predictive analytics with external data added in) and here is the biggie - the data footprint is 37-50x smaller as you get rid of all material aggregates, joins, secondary indices and more. also app development and management is easier. These are amazing properties to take to the cloud - as cloud is all about simplicity, instant transactions & analysis and is always-on.
The facts are that suite on HANA is here with many live customers already, many LOB applications like S&OP on HANA and industry applications like Fraud Management in Financial Services built natively on HANA are here already (dont get the facts behind Mark's 2020 comment - did you fact check it? On the other hand from riducling cloud to doing a 180 turn and embracing it, customers and industry watchers have a long memory!)