Regarding travel plans during/after H1B transfer approval.

Hello, On FEB/2012 I got my H1B stamped with ABC employer. I got stamped for 3 yrs starting from OCT-2011. Now i got an offer from XYZ employer and they filed for my H1B transfer, as per the online status the trnasfer got approved. But, due to some critical situations i have to go out of country (Home Country) on DEC-02 before I get my transfer papers. My new employer mentioned that once he receives all documents from USCIS he is going to post them to my place. Below are my questions/doubts, 1) Do i need to get stamped again with new I797 (from XYZ company) when my current I797 (from ABC) is valid for another 2 yrs ? 2) Do i need to show my new I 797 (from XYZ company) at port of entry so that my I 94 will get most recent H1B expiry date. 3) Appreciate if u post any suggestions. thx