I've not been active here for long but I've got many PMs and have been able to talk to many of you in here (including lurkers) regarding what I did and how it worked out. I assume it is about time I post it here. If you wish to know more info, PM me.
I initially decided to take the H4 route and not bother with applying for F1 etc as my I-140 was approved and I didn't want to risk not getting F1.
I finally took an unpaid sabbatical from my company and started my MBA (on H1B). Around November, I figured that finding an internship outside of USA and on top of that returning to USA from the internship on an H1 (but on sabbatical and studying full time) might be even more complicated. So I mustered courage, prayed a lot and took the leap of faith. Yes, in other words I applied for an F1 CoS in Nov/Dec.
I consulted many lawyers and eventually used a lawyer in NYC who was referred by a friend. (If you need details, PM).
The lawyer helped me out and we successfully got a F1 approval CoS around Feb, 2011. I resigned from the employer once the CoS got approved.
I went to India during spring break and got my F1 stamped without any trouble.
Now, as per my lawyer if the next employer of mine post MBA applies for GC, they should be able to use my approved I-140 and request USCIS to use same priority date. But then again, no guarantee if they will use it or not. I'll find out that when the time comes.
For now, I'm happily interning in the fields of my choice in NYC.