Working on L2 EAD and H1 petition approved

[infovisa]

Hi,

I am currently on L2 visa valid till April 2010 and working with Company A on EAD which is also valid till April 2010. Company B had filed for my H1 B in 2008 H1 lottery with Consular Processing option.
I need to know, in case I get my H1 approved petition (although I haven't heard anything yet) :
a)Will it be mandatory for me to switch to H1 visa from 1st Oct 2008 ?
b)What if I go to India after 1st Oct 2008 and come back without getting it stamped? First of all, Can I do this? If yes, when I will come back to US, will my L2 be valid? as well as my EAD card?

I am really confused and will appreciate your quick response. Thanks so much in advance !

[txh1b]

a. Yes. Look at many other threads on same topic and the FAQ for H1b from the main page.
b. You can continue on L2 only if you leave before Oct 1st re-enter on L2 after Oct 1st. EAD is valid if your status is L2.