Coming soon....
The "Big Four" (with their ~20% vote quotas each) are the hosts - the live studio audience are a bunch of folks making up the remaining 20% of the "cut" (a fixed number of seats in the studio).
The public at home (with their Foxtel-Interactive handsets) listen to the on-air discussion, frantically trying to figure out which of the folks on the TV might actually deliver their vote where they want it to go. The deadline for the vote draws near.
... outside the studio door are a second tier of shady "agents", wielding mobile phones, and collecting votes via blog adverts and talk-back radio, in the purported hope of getting a seat in the studio audience, but meanwhile passing "their" votes along in blocs behind the scenes, potentially changing the balance of power after the on-air negotiations and agreements have been made, but before the final votes are cast.
...the votes are cast, and BINGO! - as the numbers appear on the screen, the studio audience gasps - the new Anti-terrorism Bill is defeated!
...but wait, news just in...a BOMB has just exploded at the HQ of the Australian occupation force in West Papua, killing three conscripts...
...a new vote is called for...one of the "Big Four" (who once played Madge on Neigbours) is suddenly demoted and asked to swap seats with a red-faced member of the studio audience (a pig shooter), while other studio members are escorted out and new ones enter the studio to take their seats.
A new quickly revised Anti-Terrorism Bill is presented (now including the death penalty) ... and a vote is called... this time, as the result flashes onto the screen, the audience cheers. The Bill is passed!
Nevertheless, despite the dramatic events of the day, the live Cricket from New Zealand still beats The Parliament Show in the ratings. Foxtel executives scratch their chins and ask themselves the age-old questions - "Why is the Australian voting public so apathetic?", "How can we encourage greater participation?", and "Dammit, how can we raise our advertising revenue?".
That's the dynamic I see emerging under the proposed system. You wouldn't need a large number of active "fiddlers" to create a volatile effect.
I just do not think a "change your vote at any time" system is practical. Not because it is not technically possible to count the votes, but because it makes a nonsense of any kind of representation which is intended to exist. Representation creates the separation which filters out emotion and passion and enables considered decision making. It also encourages professionalism in politics which is desirable when important policy decisions are being negotiated. Professional representation also reduces the likelihood of mob tyranny.
The practicality of the TV Parliament system could be vastly improved if Foxtel sent out a list of Bills pending for the coming month (along with their program guide), and people were only able to change their vote once a week (say). This however would essentially destroy the true "proxy" nature of the system.