Parents might not like their children playing Vampire - The Masquerade: Bloodlines. It is fairly bloody and contains many mature themes and images, though it does not present them in the juvenile fashion of many bloody games. Fans of the Vampire - The Masquerade license may have mixed feelings about Bloodlines. It doesn't adhere as strongly to the pen & paper version as Redemption did, though many of the basics such as the stat and clan system are there.
Fans of classic, party-based PC RPGs may or may not like Bloodlines. It's is a number crunching RPG at its core, but it is definitely in more modern style of FPS/RPG hybrids like Deus Ex and System Shock 2.
Fans of Deus Ex should love Bloodlines, since it offers a similar combination of atmosphere, strong writing, character customization, and narrative depth.
Fans of games like Fallout, Planescape Torment, and Knights Of The Old Republic who thirst for complex and literate stories in RPG's should be happy with Bloodlines. Its story and characters are easily its best aspect.
Deaf and hard of hearing gamers may some trouble with Bloodlines. It provides subtitles for all dialogue, and the well-designed facial animations should make conversations understandable, even without voice. However, there are moments during combat and sneaking that aren't communicated well on a visual level, like when a character sees you from a distance. Players may be able to fiddle with their play style in order to account for this (after all, it is possible to favor stats that reduce the player's reliance on audio cues) but it might be difficult anyway.