Still listening, but a quick note on Mass Effect DLC as it relates to Kasumi: if you never bought the Kasumi DLC pack for ME2 (I didn't) she actually never shows up in the game. I suppose its neat that the game even takes into account your time (or lack thereof) with the dlc, but it would have been neat to meet that character. Not a big deal though.
To me, the Kasumi DLC is a great argument for day 1 dlc.
I purchased it the day it came out, but I was already done playing ME2, so I did her mission and that was that. Already, had I been able to use her throughout my playthrough, it would have made that a better $7 value, but as it stood, I got to use her in one mission. (still not complaining, it was entirely worthwhile)
And then, when I imported my ME2 character to ME3, I chose the save file from when the game was completed, so I had not yet played Kasumi's mission. I had NO IDEA that she was in ME3 at all until I saw my fiancee run into her.
If the Kasumi DLC was available on day 1 I would have had her for my whole playthrough and I would have had access to her content in Mass Effect 3.
Yes, I could just replay both games.. but its not a great solution compared to "just buy the DLC whenever you want or not at all"
Also, I disagree with Wombat's argument about the Shadow broker stuff. The events there essentially took place between ME2 and 3(the timeline really isn't important since it has no bearing on the story of ME2). I can think of dozens of movies where characters go on living between the slices of their lives that we get to see in their sequels. Essentially all you need to figure out is "Liara is now the shadowbroker". I have to assume it's explained in the ME3 Codex if you need more information about that.