It makes more sense than the other way around: PvZ is probably the most famous of the Popcap games, and Peggle Nights is the sequel to Peggle.
Hm. I guess it's just me, but I figured that everyone who wanted to play PvZ would have by now--it's been released damn near everywhere so I can't imagine it's still making PopCap a ton of money, but I'm sure I could be wrong.
If one of today's Humble WB Bundle bonuses does end up being Guardians of Middle-Earth you may be interested to know that there are a couple of Raptr rewards for DLC. One requires you to be http://raptr.com/dashboard/rewards/guardians-company-of-dwarves in the game and the other requires http://raptr.com/dashboard/rewards/guardians-warriors-bundle status so you won't be able to qualify immediately, but it might be incentive to put the game on the front of your list and maybe do some idling if you plan to play much of it and will use the DLC.
Well, I played a bit of it when it first showed up in the free PS+ list, but it's not that much fun, IMO. As much as I usually enjoy LoTR-themed games, I don't think MOBAs are my kind of thing. It reminded me of all of the reasons I didn't care for Company of Heroes--it was too much like actual trench warfare. I would spend a lot of time and resources trying to control an area only to lose it to the AI and then have to recapture that area--wash, rinse, repeat.