How wonderful it would be if Greg Kotis's play was a rapid response to David Cameron's alleged interest in porcine affairs. Not only wonderful to those still laughing about the imaginary high jinks at Oxford 20-odd years ago (the story will never not be funny), but a whole lot more dramatic and amusing than Pig Farm is in reality.

Rosalind’s “working-day world” takes an unexpectedly literal turn in Polly Findlay’s sparky new As You Like It for the National Theatre. An opening sequence, set in a windowless trading-floor, opens out in one of the year’s most bewitching set transformations into a brown and scrubby Forest of Arden, whose flowers bloom all the brighter for their delayed appearance. The action too, stilted at first, blossoms as Arden works its magic, delaying but not ultimately denying us the pastoral comedy we signed up for.

It trashed Olivia Newton-John’s film career, halted the movie-musical revival, and was so critically reviled it led to the creation of the Razzies. How, then, could the stage version of hubristic 1980 flop Xanadu become a 2007 Broadway hit? The answer, as illustrated by Paul Warwick Griffin’s sublimely silly Southwark Playhouse production, is to laugh at itself first.

After 12 seemingly idyllic years, Tom and Beth’s marriage is over. That’s a concern for Gabe and Karen, partly because they care for their friends, and there’s the ugly business of choosing sides, but mainly because it causes them to call into question their own previously impervious union. In Donald Margulies’s ruminative 2000 Pulitzer Prize-winner, solipsism rules.

Never use one word when you can get away with two: that seems to have been the maxim of Eugene O’Neill even in one of his shorter plays. After all, when is an ape not hairy, and why does stoker Robert “Yank” Smith, a natural hulk brought low by mechanised capital, have to bang home the title at every opportunity? Yes, this must have been an astonishing play to see on Broadway in 1922, and it still gives director Richard Jones a chance to throw every stylised trick in his very singular book at its eight diverse scenes. But masterpiece it isn’t.

Remember back when David Hare was left-wing? I’m not sure that he does. Between the affectionate, bittersweet nostalgia of South Downs and now The Moderate Soprano – a stroll through the verdant history of England’s most exclusive opera company – we’re suddenly a long way from the school of Slag or the urban anger of Racing Demon.

If the thought of three hours of DH Lawrence fills you with dread, fear not. Ben Powers’ inspired melding of Lawrence’s trio of mining plays births a spellbindingly intimate epic with atmosphere thick as the coal dust engulfing this cloistered 1911 East Midlands village. The community is powered and oppressed by the industrial machine swallowing up the menfolk, but our focus is on the women’s claustrophobic domestic sphere.

Once upon a time, quite recently, you couldn’t move for plays about youth. Now, there’s been an avalanche of dramas about ageing, usually in the context of dementia and family life. Maybe all of our main playwrights have suddenly grown up, or maybe the endless quest for novelty has deposited us on the shores of the current trend-setting idea. Nicola Wilson’s Royal Court debut is yet another play about Alzheimer’s, ageing and memory, but is it any different from Florian Zeller’s The Father, April de Angelis’s After Electra or Emma Adams’s Animals?

On my way to see this show, I had to walk across Soho. No fewer than five people asked me for money; one was a real hassle. Yes, I know that the government says that the economy is booming, but the record number of homeless in the capital tell a very different story. Yes, I bumped into five of them in 15 minutes, although I know there are thousands more. And maybe one of them is Joanne.

Tom Morris has a strong feel for drama that explores the personal implications of fanaticism: his production of John Adams’s powerful opera The Death of Klinghoffer for New York's Met and the ENO, used a language of great simplicity that allowed the work’s most disturbing complexities to come through with formidable power. Once again with Arthur Miller’s The Crucible, an equally rich text, there is a stripped-down quality to his overall vision, supported by a generally superlative cast and finely tuned pacing.