I don't see Virgin Atlantic every becomeing the same as Virgin Australia, in terms of challenging the dominant carrier.

BA isa bit smarter than Qantas and has constrained airports to their advantage

When all BA flights consolidate to 2 terminals, will the third terminal(3/1) be an all Oneworld terminal besides BA??

Currently the whole alliance has 3 terminals at Heathrow, hopefully this does not reduce to all of them in only 2 terminals after this ( unlesss each terminal is becoming larger)

T1 is to be demolished after the new T2 opens in 2014, so I would say that oneworld will end up in T3.

so if T1 is being demolished this means that the Oneworld alliance is not going to fit itself , including a larger BA into 2 terminals from three!!

Why would someone fly a oneworld airline then if they have an alternate on the route, after all they will be huge queues if a bigger(by then) alliance moves into a smaller area

My two cents: I don't think that OW won't fit per se. I'm with madge on the guess that OW will most likely end up in T3.

The only OW carrier in T1 is BA - and that's simply by virtue of having purchased bmi; hence it's only natural for BA to move everything to T5 and T3 where BA already operate (pre- and post-bmi purchase). T1 at the moment is essentially a Star Alliance hub.

Hence, with respect, I would disagree with Kash in saying that the whole alliance has three terminals as T1 is, in the grand scheme of things, relatively insubstantial. BA always stated that its intention was to integrate bmi into its own operations, so from the start the cost synergies were always going to be in the realm of consolidating operations across its pre-existing terminals; the fact that it was forced to sell landing slots (ultimately to VS) simply accelerated this by requiring them to reduce the legacy bmi presence in T1 in any case. 

Hence - notwithstanding the fact that queues are horrible in any LHR terminal (barring sometimes in T5) - I don't think that there'll be any substantial impact as the alliance really won't be 'mov[ing] into a smaller area'.

That being said - it is worthy to note that T3 isn't a pure-OW terminal. It also hosts other airlines such as Virgin Atlantic and Pakistan International from memory. 

And plenty of posts on the web inc airliners.net that Virgin Atlantic (VS) wants to become the anchor tenant for T2.

So that would open up plenty of space in T3 for the ex-BMI operations.

Then to complete the terminal they just needs to extent the T5/T5B/T5C underground train to T3/ future 5D/5E, then you have a perfect oneworld terminal.