Massimo plays the role of expert explaining the problems with memetics. Julia plays the role of sidekick, struggling to understand Massimo's position, but having some sympathies to memetics. Those dynamics are quite fun. However, it seems to me that not too many problems are convincingly raised, and there's a lot of arguing via "I don't see how" and "it is not clear how you would do that"-style material. That doesn't work too well here: either I can see how and I do know how you would do that - or else I can explain why it it shouldn't be seen as being an important issue in the first place.
Julia Galef says at one point that she hasn't actually read anything from the Journal of Memetics. Hmm.
This is "armchair philosophy" material. They don't really mention any of the actual science involved.
Massimo says at one point that his biggest objection is that there's no ecological science of memetics which makes predictions about which memes are fitter than other ones.
This area is part of what is often called "Applied Memetics" (which also includes memetic engineering). It seems to be one of the better studied areas of the field to me - simply because social media marketing and advertising departments need to be able to predict what spreads and what doesn't in order to be able to construct successful viral marketing media.
Francis Heylighen's 1998 paper "What makes a meme successful? Selection criteria for cultural evolution" gives an early introduction. More recently, there have been many studies of social media on the internet that look into this sort of thing. For instance see, Dan Zarella's The Science of ReTweets. Of course we don't know everything about this field, but it is a challenge in organic ecology too.
If Massimo wants to understand the relationship between gene-culture evolution and memetics, a fairly sensible (if rather snarky) take on that is Mathematical models for Memetics by Jeremy R. Kendal & Kevin N. Laland. In a nutshell, these are different groups people approaching the same material from different angles and drawing extremely similar conclusions. Memetics has much better terminology, visualisation and visibility - and gene-culture evolution has much better studies, data and credibility within academia. The historical attempts by both parties to criticise each other appear to have been fairly uniformly hopeless and stupid. Now that we have the internet, it seems obvious that these groups should work out their differences and combine their forces.
The critics of memetics don't make too many videos, it seems, but a podcast is better than nothings - and so I might try a response video or two quoting Massimo and Julia at some stage.
Update 2011-09-30 - I respond here. Also, Massimo writes his ideas on the topic up here. Massimo still seems very muddled to me. He raises much the same objections as in the podcast, and approvingly cites the academic cultural evolution literature - apparently without realizing that it is saying a lot of very similar things to memetics - and that many of his objections are equally applicable to it.
Update 2014-07-30: Julia seems to have become quite a meme enthusiast. For example, she attributes human progress to memes many times here. Go, Julia!