Honestly, I'm a HUGE believer in a soul link spec, and while its true you can't pick up ruin for a nice dps increase for pve, you can tell a HUGE difference in your survivability.
Personally, I'm not a huge fan in going deep into aff for nightfall with soul link (while that is certainly a path you can go down), I like picking up shadow burn as its a much more reliable instant cast you can use (so long as your willing to keep your shards in decent supply). Even more, going for shadowburn gives you an excuse to put points into bane which will make you significantly more valuable in 5 mans. I just think its an all around good spec. Here's what I use:
http://db.vanillagaming.org/?talent#IVZbxuzgxotZxx0zNow, there are a few talents that I would consider debatable as to whether you want to pick them up. I go with imp voidwalker, because it helps with soloing a bit, gives you a better shield if you decide to sacrifice it, but really you could go with 3 points into any of the demons of your choice. A second talent I pick up is isb instead of cataclysm. I could see the argument for cataclysm, as it will save you some mana (albeit a very small portion of your mana).
Last, I didn't use the last 4 talent points. Personally, I dump them all into aftermath, because you might be able to get a lucky aftermath proc after a shadowburn or, if your not under attack, and you're spamming searing pain or shadowbolt its a nice addition to the damage of those spells. However, I could totally understand putting those last four talents into devastation or imp lifetap (and aftermath or devastation with the remaining two). Honestly, the choices you have at that point are somewhat limited (although maybe I'm bad for not picking up imp LT it really is a significant mana boost to your lifetaps), and I can see good arguments on all sides.
Of course, this isn't a raiding spec, but it should do perfectly fine in 5 mans where the min/maxing dps isn't as big of a deal (but to be honest the dps requirements for MC isn't really a big deal either) simply because bane is the largest pve dps increase a warlock has. It is really painful for me to group with anyone without it and I just feel like my dps is significantly gimped without it.