Yeah, the game kind of forces the Eagle Vision on you. When Desmond steps off the Animus for the last time, he gets a brief flash of it and says "What the hell?"
As for Vidic's pen, you have to exit the Animus mid-game. Lucy will stay at her computer and ask you to sit down (to get back in the Animus), Vidic is standing by the window and will yell at you to sit down. If you walk up behind him, there's a "Press any button to interact" thing, and when you do, Desmond quietly slips Vidic's pen out of his pocket and sticks it up his sleeve. From that point on, in the normal "interim" parts when the others have left the room, you'll have access to Vidic's computer. And you need that in order to get into the conference room.. Lucy emailed the password to Vidic when security changed it. Come to think of it, you might find it in Lucy's Outbox. But I've noticed that some things work automatically before you've read them, so I imagine if you don't have access to the conference room, you've missed the chance.
The information's out there, though. There's only one thing in the conference room, a computer terminal. And only one email on that terminal, the contents of which have been reposted to the internet. It sums up the status of several other Abstergo projects involving ancient artifacts:
It mentions the Piece of Eden (No. 3), indicating that #2 was lost in the accident in Denver that Lucy talked about. No mention of #1.
It mentions a time-travel device of some sort that was used in the Philidelphia Experiment in 1943, and was determined too dangerous and therefore locked away (with a mention that they don't wish to meddle in time travel for fear of paradox, so any other time-travel devices they eventually discover are to be immediately locked up and not used).
They mention the Tunguska blast as being caused by the destruction of a wave-generation device when the compound was destroyed by the Assassins, and that they hope to find more devices like it.
They mention the Holy Grail, and a growing suspicion that it doesn't exist, and will therefore be removed from the priority list of things-to-acquire.
The last thing they mention is what they call "Mitchell-Hedges Communicators", and that they work for ultra-secure communication, but are limited in number. I didn't realize it right away, but they're also based on historical artifacts. Namely, crystal skulls, which are reputed to give the bearer some psychic ability, and there are supposedly thirteen of them scattered about the globe. I imagine that if you looked at the skulls as being technological devices instead of mystical (like the Piece of Eden), then the apparent "psychic" abilities would in fact be communication between skulls, similar to the Palantiri of LOTR. As an interesting side note, the next Indiana Jones film is supposed to be related to this.
It's interesting to consider the devices in question, though. What are they? The Piece of Eden is clearly a technological device and not "magical". Was it contructed eons ago, left behind by some ancient civilization? Left behind by aliens? Built in the distant future, inadvertently (or intentionally?) left in the distant past? Are all of these various devices (the time-travel device, wave generator, crystal skulls, etc) all built by the same race? What will we find out about them in future installments?
I actually like the way they did that... It really does remind me of LOST, where they feed you just enough information to bring you back for the next episode, begging for more.. hehe.