Another day, another Level 12 alt trolling the Warlock Forums with a "QQ NERF" thread. Except that this particular thread is currently at 8 pages long and involves some pretty interesting discussion. The OP suggests that adding a cast time to Lifetap would be a good way to help balance the Warlock for PvP play. However, many 'locks point out that it would also gimp PvE DPS, and would have varying effects on each talent tree and what not. Definitely a read worth looking into. And yes, even if it entails sifting through some standard "gtfo noob" spam.
Have fun. =)