Burlington Arcade's independent traders face the (leather) boot, Frank Gehry eats humble pie and Scotland gets a bridge made entirely from recycled plastic

The protests at St Paul's Cathedral are getting all the attention, but for a certain echelon of London society, the real battle is going on at Burlington Arcade, whose proposed £5m redevelopment has galvanised conservationists, traditionalists and Michael Winner. For the uninitiated, Burlington Arcade is the posh people's equivalent of Diagon Alley from Harry Potter – a secluded, beautifully preserved 19th-century arcade whose historical opulence is matched by the retro luxury wares of the outlets, such as vintage fountain pens, handmade shoes, cashmere scarves and dragon bridles – well, maybe not the last one. The Grade II-listed building has been acquired by retail investment firm Meyer Bergman and the ominous-sounding Thor Equities, and the plan is to replace all those independent traders with high-end fashion brands such as Prada and Jimmy Choo.

Few people have seen the actual designs, but one suspects the Arcade brigade are not encouraged by the architect: New Yorker Peter Marino, who specialises in upmarket fashion stores. Not only has Marino stated that his work is not built to last, he likes to dress in black biker leathers, accessorised with sunglasses, leather cap, leather gloves and straps around his biceps. It's not yet clear if Burlington's top-hatted beadles will have to dress the same way, but Marino's look is a sign of how architects' style has moved on. Gone the days are when some Issey Miyake (à la Zaha Hadid) or a pair of Le Corbusier glasses qualified as sartorial flamboyance in design circles, now you've got to look like a missing member of the Village People. Take note, British architects, and up your game!

Talking of architectural flamboyance, Frank Gehry has not been having a good time of it recently. Last week, the 82-year-old designer was forced to acknowledge criticisms of his ambitious design for the Dwight D Eisenhower National Memorial in Washington DC. In terms of memorial architecture it's a radical departure, proposing giant tapestries of woven stainless steel held up by huge stone columns, which effectively screen off the building behind them. The size of this $90m-plus project has caused much public consternation. Three of Eisenhower's granddaughters even issued a statement expressing concern about the "concept for the memorial, as well as the scope and scale of it." "The people are asking good questions," Gehry acknowledged, doubtless wondering if he shouldn't have just given them another Bilbao Guggenheim and have done with it.

Then again, Gehry's Abu Dhabi Guggenheim also hit trouble this week, when it emerged that the company building it had withdrawn the contract for the concrete work and was "reviewing its strategy". The government-backed gallery, which will sit next door to a branch of the Louvre and new museums designed by Jean Nouvel, Zaha Hadid and Norman Foster, has already had its opening put back from 2013 to 2015. There are now rumours it's to be cancelled altogether. These have been denied by the Abu Dhabi side, but the project seems to have stalled, at least temporarily.

On a more optimistic note, Europe's first road bridge made of recycled plastic opened this week in Scotland. Crossing the river Tweed in Peeblesshire, the 30-metre-long bridge was made from 50 tonnes of household recycling material, such as drinks bottles, and took just two weeks to put up. That's got to be better than shipping our plastic to China for recycling. Added to which, this thermoplastic composite material has several advantages over standard materials such as timber, steel and concrete: it never needs painting, it won't rust or rot, and it's 100% recyclable. The technology was developed in the US but it's being made in Wales by a new company named Vertech. As well as bridges, they hope to develop a range of recycled sheet materials to replace plywood and MDF in construction, which suggests an entirely recycled plastic house is now possible. Who'll be the first to do it?

And finally, looking much further into the future, who can resist an event called Thrilling Wonder Stories? This is the Architectural Association's third annual speculative sci-fi-inspired design jam, where architects are invited to think way out of the box, their imaginations cross-fertilised by "mad scientists, literary astronauts, design mystics, graphic cowboys, mavericks, visionaries and luminaries". They're not joking. Guests in London this Friday and Saturday (there's a parallel event in New York) include Vincenzo Natali, director of warped sci-fi movies Cube and Splice, author Bruce Sterling, taxidermy artist Charlie Tuesday Gates (hosting a live workshop) and special effects supremo Andy Lockley, the man who folded up Paris in Christopher Nolan's Inception, among other feats. It's the shape of things to come, you know.

• This article has been amended. The original stated that the bridge made from recycled materials was 9 metres long and in Wales. This has been corrected.