Seems like its going ahead, raising the capacity to 40k by time of Ashes in 2023 to make it the biggest ground in England.
Surrey raising the financial stakes year upon year with many sold-out games and many business units to be utilised in the ground.
https://www.standard.co.uk/sport/cricket/surrey-reveal-50m-redevelopment-of-the-kia-oval-a3824016.html 
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It seems work will start after the summer of 2019
http://www.skyscrapercity.com/showthread.php?t=441550&page=9
Actually think thats one of the catering issues they should be addressing. They should allow for an option for a 'decent' lager , like say Leffe on draught at a slightly inflated price to put off the chavs and hoorays- then we could all have a good kip in the afternoon- after all, isnt that what we all secretly go to cricket for?!
Seriously, i once got threatened with ejection from Lords from one of their stuffy (Dads Army) stewards for falling asleep in the Grand Stand sprawled across 3 seats on the last, boring day of a Test match v SA, as he didnt like the fact that the match was so boring ( it was the game where Smith batted for about 2 days for about 80) and that Sky had picked up on it and decided to show me on the big screen and live on Sky Sports too. First person to be ejected from a cricket ground for falling asleep.
However, I don't think much of the new design (considering what it maybe could be).
I'm not liking the no roof in particular. Perhaps it wouldn't be approved, due to height restrictions ?
I was the cricket organiser. Every year I'd take a group of hairy arsed coppers (& that was just us women) to a Pro40 & T20 game.
I'd usually try & make sure the T20 was v Kent for obvious reasons.
Brilliant venue & never ran out of bitter.
Happy days
The Oval, as you know, is one of the biggest playing areas in the country,with one of the biggest squares in the country too, and i've always had problems with viewing when seated low down, especially if the strip is towards the other end of the square. Its never, imo, been the best of views, seems lke a long way away -but, being that the new stands are higher, then the viewing should be better.
Also, i would expect, in the Test arena, that when India come touring,despite their apparent recent decline in Test atendances at home, that they will fill the venue too, maybe not every day, but maybe sat and sun - so, every 2 years at least, but i fully expect some of the 20/20's (Kent,Essex,Middlesex) and especially the '100' games to be full or near full for every season- there is a huge demand from the City for post work sporting events.
If they ever find a way of using the Olympic Stadium for T20 cricket, that could be an interesting alternative too. Apart from Essex fans, it's easy to get to for Kent fans too.
As for the view at The Oval, I was a member for many years and still love the view from the Pavilion Terrace (and the beer is cheaper in the Members' Bar!
Now I more often sit with the masses but was very impressed with the view from the new Peter May Stand where I sat for the ODI v West Indies last year and I'll be in roughly the same spot for a day of the India Test.
I can compare it to the Adelaide Oval, a huge 70,000 seater stadium which is very comfortable but many spectators are so far away from the action. Give me Kennington over Adealaide any day!
That area is one of the few spaces where spectators have room to move about and access the various food outlets there. Once built over, it's going to be even more cramped there, it's a nightmare now to walk around the Lock/Laker side of the ground, they could do with cordoning off the road to allow circulation outside!
I know its not down to Surrey but I hope something is done at Vauxhall station as it's a nightmare now getting home even when it's 3/4 full, god knows how bad it would be with 40k trying to get a train!
Poor airflow and heavy shade can cause a major deterioration in the playing surface.