A Pink Floyd tour would absolutely murder everything that's ever been done in terms of revenue. The fact that a promoter was offering $250 million to these guys to go on tour (that they they turned) down speaks volumes.
This is pretty timely...last night I went to a Classic Albums Live show at the Phoenix in Toronto, a terrific series of shows that have seen them cover the Stones' Sticky Fingers, the Beatles' Abbey Road, U2's Joshua Tree and Rush's 2112 in their entirety (I attend the last two shows). Last night they performed Floyd's Dark Side of the Moon, and as usual it was just a stellar performance. They also performed some other tracks (as they usually do), including Sheep, One of These Days, and of course Comfortably Numb. They're gonna cover the Wish You Were Here album in a couple weeks, and it should be another fantastic show.
Oh yeah, I bought a handful of Floyd albums about a month ago based on the recommendations on this board, with most of 'em being sold at special prices. So far this is my order of preference...
Animals
Wish You Were Here
Echos (not sure if that counts, but whatever)
The Wall
Dark Side of the Moon
UMMAGUMMA (just a bizarre album, but I liked the live stuff)
Echos is interesting in showing how ridiculously different the Sid and post-Sid stuff appears to be. I can't say I've ever been into that psychadelic sound, but if there were other styles they performed during that era I'd be interested in knowing.
One more Floyd related note...the Live 8 DVD is due out November 7th as a four disc set, with almost all the London and Philly sets being shown in their entirety (some of the acts got their sets reduced), and a behind the scenes look at the Floyd rehersals. Here's the full track list.
Disc One:
"Sgt. Pepper's Lonely Hearts Club Band," Paul McCartney and U2
"Beautiful Day," U2
"Vertigo," U2
"One," U2
"In My Place," Coldplay
"Bittersweet Symphony," Coldplay with Richard Ashcroft
"Fix You," Coldplay
"The Bitch Is Back," Elton John
"Saturday Night's Alright for Fighting," Elton John
"Children of the Revolution," Elton John with Pete Doherty
"7 Seconds," Dido and Youssou N'Dour
"Bartender and the Thief," Stereophonics
"Everybody Hurts," R.E.M.
"Man on the Moon," R.E.M.
"Dy-Na-Mi-Tee," Ms Dynamite
"Somewhere Only We Know," Keane
"Where Is the Love," Black Eyed Peas
"Let's Get It Started," Black Eyed Peas
"Get Up Stand Up," Black Eyed Peas with Stephen Marley
"Wild Boys," Duran Duran (Rome)
"I Don't Like Mondays," Bob Geldof
"Time Is Running Out," Muse (Paris)
"Sing," Travis
"I Predict a Riot," Kaiser Chiefs
"Everyday I Love You Less and Less," Kaiser Chiefs
"Reasons," UB40 with Hunterz and the Dohl Blasters
"Red Red Wine," UB40
"American Idiot," Green Day (Berlin)
"Signs," Snoop Dogg
"Who Am I (What's My Name)?," Snoop Dogg
"Livin' on a Prayer," Bon Jovi
"Why," Annie Lennox
"Sweet Dreams," Annie Lennox
Disc Two:
"Survivor," Destiny's Child
"Girl," Destiny's Child
"Somewhere Else," Razorlight
"Golden Touch," Razorlight
"All for Love," Bryan Adams (Toronto)
"Diamonds From Sierra Leone," Kanye West
"Like a Prayer," Madonna
"Ray of Light," Madonna
"Music," Madonna
"Getting' Jiggy Wit It," Will Smith
"Switch," Will Smith
"The Fresh Prince of Bel Air," Will Smith
"Good Vibrations," Brian Wilson (Berlin)
"Run," Snow Patrol
"Stays in Mexico," Toby Keith
"All These Things That I've Done," The Killers
"American Baby," Dave Matthews Band
"Bad Day," Daniel Powter (Berlin)
"In the End," Linkin Park
"Numb," Linkin Park with Jay-Z
"Super Duper Love," Joss Stone
"Some Kind of Wonderful," Joss Stone
"Show You Love," Jars of Clay
"Laura," Scissor Sisters
"Take Your Mama," Scissor Sisters
"For All We Know," Alicia Keys
"Fall to Pieces," Velvet Revolver
"Pour Some Sugar on Me," Def Leppard
"Are You Gonna Be My Girl?," Jet (Toronto)
"Angel," Sarah McLachlan and Josh Groban
"Message in a Bottle," Sting
"Driven to Tears," Sting
"Every Breath You Take," Sting
Disc Three:
"Make It Happen," Mariah Carey
"Hero," Mariah Carey
"When You Come Back," Vusi Mahlasela (Johannesburg)
"Do the Strand," Roxy Music (Berlin)
"This Love," Maroon 5
"She Will Be Loved," Maroon 5
"Four Strong Winds," Neil Young (Toronto)
"Go West," Pet Shop Boys (Moscow)
"We Will Rock You," Robbie Williams
"Let Me Entertain You," Robbie Williams
"Feel," Robbie Williams
"Angels," Robbie Williams
"Somebody Like You," Keith Urban
"Twenty Years," Placebo (Paris)
"Lonely No More," Rob Thomas
"We Come 1," Faithless (Berlin)
"Master Blaster (Jammin')," Stevie Wonder
"Higher Ground," Stevie Wonder and Rob Thomas
"Signed Sealed Delivered," Stevie Wonder and Adam Levine
"So What the Fuss," Stevie Wonder
"Superstition," Stevie Wonder
"Who Are You?," The Who
"Won't Get Fooled Again," The Who
"Speak to Me," Pink Floyd
"Breathe," Pink Floyd
"Money," Pink Floyd
"Wish You Were Here," Pink Floyd
"Comfortably Numb," Pink Floyd
"Get Back," Paul McCartney
"Drive My Car," Paul McCartney and George Michael
"Helter Skelter," Paul McCartney
"The Long and Winding Road," Paul McCartney
"Hey Jude," Finale
Disc Four: Extras
Highlights from the July 6th Murrayfield concert in Edinburgh
"All About You," McFly (Tokyo)
"Lifestyles of the Rich and Famous," Good Charlotte (Tokyo)
"Love Love Love," Dreams Come True (Tokyo)
"All Is Full of Love," Bjork (Tokyo)
"Who Are You?"(film), The Who
"Why Does It Always Rain on Me?"(film), Travis
"Enjoy the Day," Ricky Gervais
Behind the Scenes at Hyde Park
Pink Floyd rehearsal
Im salivating at the mere prospect of new Floyd material and or Tour. 
I'd be more interested in a world tour...