Last monday I attended the first day of the Lisbon Office 2013 DevCamp, were the focus was mainly on Apps for Office and Sharepoint.
Well being a Sharepoint person, I had to attend.
The known concept of Apps applied to Office and Sharepoint seems to be most promising, nevertheless it makes us to think in a different way on developing.
Well the Apps are IN so why not take advantage of this hype and develop in a new and more attractive way.
Try to look at it in terms of business, you can make money from your simple development.
Client Side Object Model is extended, and in a BIG way, almost every Server Side interface are exposed in the Client Side nowadays.
A very rapid ramp up on development and deployment.
Cleaner and more simple acquisition and installation methods.
No more SandBox solutions (this one personally is positive :) )
Cannot be used in Farm level or Full Trust.
Probably you will need to reprogram your already existing code, to be used in an App solution.
To sum up:
It is a very exciting new way of developing, that together with eDiscovery and Comunities make for me 3 of the main features to look up to in Sharepoint 2013.