L1-B extension - H1B COS

[rgupta2]

Hello Friends - I need some advise from you, I am currently working on L1 Blanket and my wife works for same organization on L2+EAD.

I129S is valid till 21st July 2012
L1-B VISA stamp is passport valid till 21st July 2012
I797 is valid for indefinitely
I-94 is valid till 5th December 2013

A extension request for my L1-B was submitted by my company,but my I-94 was valid.

Apart from this a new H1B 2013 request submitted.

I am in US now,

Last week I got a RFE for my L1-B extension, which should be replied by 11/18/2012
Today I also got H1B approval, but with COS , It also contains a I-94 valid from October 1st 2012

Now my employers tells me that 240 day rule is not valid for COS. I am confused as I still have the L1-B I-94 valid till December 2013.

Would I have to return back immediately, Or After October 1st 2012 I automatically get into status of H1B.

Please suggest