Does the new adv. sentinel have multiattack?

yes, it does.

plus it has 2 target symbols,

so it can effectively shoot at 4 targets in 1 turn.

All Colossal Figure (the guys with this Damage symbol )have the Multi-attack. The rules for these are included with each character and also in the Legion Rulebook.

Correction: All Colossal figures so far. Being a Colossal does not in itself grant you the multi-attack power.

As per the rules published with the Advanced Sentinel, it was possible to make a capture attempt as part of a Multi-Attack. The rule was then FAQed, HEACed, or hacked so that it was not possible to do this. Then the rules in the Legion Starter were copied from the Advanced Sentinel rules.

So, how does it stand now? Can the Advanced Sentinel charge as the first part of a multi-attack and then attempt to capture?

As you've pointed out, with the switch over to LoSH, that little bit of E&C seems to have been lost. However, I doubt this was intentional and I know that I would still rule at my venue that the Sentinel could not combine the two.

It wasn't lost. It never actually made it into the E&C. The RA had posted that it would get in, but it never actually did.

http://forum.wizkidsgames.com/showthread.php?t=151590

Thanks, but I'm still not sure how I'd rule it.

The rules arbiter said 10 months ago that something ought to go into the next E&C-- but it never did, and there has been a new rulebook since then. Especially since his forum posts aren't really official... hmm...