I'd highly recommend that you be prepared for the change to Dailys that can occur after purchasing an expansion. I have an account with only core Tyria and the Dailys took about 10 minutes yesterday. I also have an account that started on day 3 of the game and has Hot, and last night I bought POF. One of the Dailys was to do a Devastation Bounty. That content appears to be at least 3 maps away from the story start. It took a long time to find this map and specific content, and about an hour more than what I can usually spend on the game each day. Of course we then need to kill a champ, apparently alone, and only after learning about it's specific abilities and attacks.
I understand the principle that Dailys should be designed to move us into new areas and new content. I don't agree with that intent at all , but I don't make the game so I go along with it. But in this case, It's totally messed up.
I don't know if this will properly address this issue but I would suggest that we not be given Dailys that take place in a location that is more than one map away from content that we have already opened. That way we are motivated to do new content and ACTUALLY HAVE A CHANCE OF COMPLETING IT, instead of literally wasting our time. Yes, I opened a few waypoints along the way but when your committed to doing new content, and the accompanying story, that happens anyway.
So, if you are considering purchasing an expansion, I would strongly suggest taking a good look at how the Dailys will change and get at least a rough Idea of where they are and what abilities and skills will be needed when you get there, so your not wasting your time.