Portal 2 Achievements revealed, prompt more Half-Life 2: Episode 3 speculation

All fifty Portal 2 Achievements have been revealed by Xbox 360 Achievements. The list is rife with the expected inside jokes and word-play (Still Alive, Pturretdactyl, Bridge Over Troubling Water), but one in particular has a the internet talking with its fingers.

The "Ship Overboard" Achievement bears the description, "Discover the missing experiment." Could it be referring to the Borealis - the Aperture project mentioned in Half-Life 2: Episode Two? Speculate away! The full list is below:

Pit Boss (30)
Show that pit who's boss
Preservation of Mass (20)
Break the rules in Test Chamber 07
Pturretdactyl (5)
Use an Aerial Faith Plate to launch a turret
Lunacy (20)
That just happened
Drop Box (20)
Place a cube on a button without touching the cube
Overclocker (30)
Complete Test Chamber 10 in 70 seconds
No Hard Feelings (10)
Save a turret from redemption
Schrodinger's Catch (20)
Catch a blue-painted box before it touches the ground
Ship Overboard (10)
Discover the missing experiment
Final Transmission (20)
Find the hidden signal in one of the Rat Man's dens
Good Listener (5)
Take GLaDOS' escape advice
Scanned Alone (5)
Stand in a defective turret detector
The Part Where He Kills You (20)
This is that part
Bridge Over Troubling Water (10)
Complete the first Hard Light Bridge test
SaBOTour (10)
Make a break for it
Stalemate Associate (15)
Press the button!
Wake Up Call (5)
Survive the manual override
You Monster (5)
Reunite with GLaDOS
Undiscouraged (10)
Complete the first Thermal Discouragement Beam test
White Out (15)
Complete the first Conversion Gel test
Tunnel of Funnel (15)
Master the Excursion Funnel
Dual Pit Experiment (15)
Do the same test twice
Tater Tote (15)
Carry science forward
Vertically Unchallenged (15)
Master the Repulsion Gel
Stranger Than Friction (15)
Master the Propulsion Gel
Professor Portal (75)
After completing co-op, complete Calibration Course online with a friend who hasn%26rsquo;t played before
Air Show (20)
Perform 2 aerial gestures before touching the ground in co-op
Portal Conservation Society (20)
Complete Chamber 3 in the Hard-Light Surfaces co-op course using only 5 total portal placements
Empty Gesture (25)
Drop your co-op partner in goo while they are gesturing by removing the bridge under them
Party of Three (25)
Find the hidden companion cube in co-op test chamber
Narbacular Drop (25)
Place a portal under your co-op partner while they are gesturing
Asking for Trouble (10)
Taunt GLaDOS in front of a camera in each of the five co-op courses
Rock Portal Scissors (20)
Win 3 co-op games of rock-paper-scissors in a row
Friends List With Benefits (50)
While playing co-op, hug 3 different people on your friends list
Four Ring Circus (25)
Enter 4 different portals without touching the ground in co-op
Triple Crown (15)
Solve 3 co-op chambers in the Mass and Velocity course in under 60 seconds each
Still Alive (15)
Complete Course 4 with neither you nor your co-op partner dying
Can't Touch This (10)
Dance in front of a turret blocked by a hard light bridge in co-op
Smash TV (75)
Break 11 test chamber monitors
High Five (5)
Celebrate your cooperative calibration success
Team Building (10)
Complete all test chambers in the Team Building co-op course
Door Prize (20)
Examine all the vitrified test chamber doors
Portrait of a Lady (10)
Find a hidden portrait
You Made Your Point (10)
Refuse to solve the first test in Chapter 8
You Saved Science (100)
Complete all test chambers in all courses of co-op
Iron Grip (20)
Never lose a cube in Chamber 6 of the Mass and Velocity co-op course
Gesticul-8 (15)
Perform all 8 gestures of your own volition in co-op
Confidence Building (10)
Complete all test chambers in the Mass and Velocity co-op course
Bridge Building (15)
Complete all test chambers in the Hard-Light Surfaces co-op course
Obstacle Building (15)
Complete all test chambers in the Excursion Funnels co-op course

We'll be getting another look at Portal 2 on March 12th at PAX East - stay tuned for our impresions!