Understand your "meh" reaction, but I think this is an exciting announcement for people outside the ecosystem. Office has been unattainable for a huge set of PC users for a very long time... it was rare to find affordable PCs with Office pre-installed. Anyone remember Microsoft Works?
Now, it's post-PC. This is opening up Office to a whole new generation of users who have found their home in tablets.
The problem is that for the subset of features supported on mobile, other tools like Numbers are comparable and have been available for free for a long time. The features that make Excel and other office products shine, including automation and macros, are not supported.
While it is a solid move for Microsoft, that whole generation of new users wont see much of a difference between 2014 office for ipad and numbers.
You don't even need to go that far. Google Drive does 99% of what 99% of users need, and has second-to-none collaboration features to boot.
I bought my wife a Chromebook as a stopgap when her last Windows laptop died, and although she still has to use Windows for work, she now swears by Drive for working on shared documents.
Now, it's post-PC. This is opening up Office to a whole new generation of users who have found their home in tablets.