第一个句子：表示预定的将来动作或对将来的预测,并非人为安排.
After you take the medicine, you will be feeling much better.
第二个句子：表示对将来的打算（区别于对将来的预测）
将来进行时的用法：
（1）表示将来某一时间正在进行的动作,一般带状语.
When he comes to my house tomorrow, I will be writing the report.
(2)表示现在正在进行的动作,但这个动作会延续到将来.
I think that she will be working on this experiment until next morning.
(3)表示预定的将来动作或对将来的预测,并非人为安排.
After you take the medicine, you will be feeling much better.
(4)表示委婉的请求
When shall we be meeting again.?
(5)表示原因
Please come tomorrow afternoon,I'll be having a meeting tomorrow morning.
(6)表示结果
Stop the child or he will be falling over.
(7)表示对将来的打算（区别于对将来的预测）
My duties will be ending in July , and I'll be returning to ShangHai.
所以自己再好好想把
http://baike.baidu.com/view/201185.htm