deus-exdeus-ex-human-revolution
At the end of Deus Ex: Human Revolution and after the credits there is a goodie with some dialog that ties Human Revolution to the original Deus Ex, which is then followed by the Human Revolution title accompanied by the original Deus Ex title music.
Is this simply an easter egg for those of us that have played the original Deus Ex or is there a more direct follow-up planned to tie Human Revolution more directly to the orginal game?
Aside from completing objectives (primary objectives earn 1000, 1750, or 2500 XP; secondary earn 500 or 750 XP; side quest bonuses earn 100, 300, or 750 XP) and the two mission bonuses of Ghost (500 XP) for getting through an area without ever being spotted by an enemy NPC and Smooth Operator (250 XP) for getting through an area without setting off any alarms, XP awards are divided as follows:
The following bonuses are all tied to entering secret areas, but the actual mechanics determining how one is awarded rather than another is still unclear to me.
(This information was adapted from Absolute Steve's FAQ on DE:HR on GameFAQs.)
Best Answer
The "Missing Link" DLC has been announced (for October), but this will apparently be set in the time between Jenson leaving Hengsha and arriving in Singapore so will not carry the story forward past the end of the game, but it may well provide more exposition on how the games are linked.
However, they have already made some fairly strong links between DE:HR and the original. Specifically, the little hidden element from the credits (that you mention) infers that Megan Reed is working with the Bob Page (and therefore the Illuminati), so is presumably using Adam's DNA to help them develop the nano-augmentations that appear in Deus Ex and the "nanite-virus chimera" mentioned may presumably result in the Grey Death.
There are also other weaker links throughout the game, for example when Jenson detonates the bomb in Hengsha shipyard he inadvertently allows Tracer Tong (a major character in Deus Ex) to escape the island. There are others too, I'm sure, but I won't try to list them all here.
A few of the Wikia pages provide more in-depth information, here's a few that are the most pertinent:
Deus Ex: Human Revolution, Plot
Adam Jenson, 2027
JC Denton, Early Life
Nano-augmentation, The beginnings