Windows phone 8.1 battery / app issue

Does anyone have any idea about what the future of windows phone 8.1 will be?

I've totally enjoyed the update to WP8.1 except for a big battery drain on my phone. I thought the new software would increase battery life (like most software updates on android) but after enjoying full day battery life (N920) I am now reduced to about a full work day battery life. Do you think this will be fixed with further software updates?

Also hardware wise the Nokia 930 (new flagship) does not have a large battery (also compared to most android flagships) and I'm not sure that it will compete well or will last me all day. Does anyone know what the future road map is hardware wise?

Another issue has been on the app front. Any idea what the latest news on whatsapp ? Why was it pulled from the store?