Hard to say off one episode, but I don't expect much to be honest; seems harmless enough though.
Going on your discussion point (have you an opinion on it?) - the trend of using pre-existing media and stories is now pretty common because it is safe(r) ground; innovation is seen as death in entertainment - you need a high amount of viewers to bring in advertisers. Pure business over creativity; although I am sure many also see it as an opportunity to reuse characters/settings/plots by putting them in a more accessible medium.
Considering a lot of anime is based off manga, it's hardly a new thing - I'm sure a lot of the anime we've watched at the club is manga-based; certainly a lot of the recent stuff like Desert Punk, Elfen Lied, Azumanga Daioh, Tenjho Tenge, Full Metal Panic (a novel there first though), Moyashimon, Spice and Wolf, Macross Frontier and Nodame Cantabile. All were Manga first according to the great wikipedia.
Recently only Last Exile stands out as being an original for-anime series; ie. not based off a manga. You're Under Arrest had some manga to base it off, apparently not much, since it is more a franchise and so much of the series was distinctly original.
One problem with the transition is often, not always, but often you get hung up compressing plot or worse padding it out to match distinct episodes. It's a common enough complaint and has obviously made a market for more directly adapted OVA's. For games; it is harder - games are long, long affairs full of dialogue (versus a book which while it might be dialogue-heavy would contain much more on descriptions so may still be adaptable).
Funnily enough I was surprised that Haruhi Suzumiya's second series had an entire set of episodes with essentially no clean breaks between episode content making what is, if viewed sequentially, a long film more then separate episodes (which is fitting considering their content). This works when the original medium; a short-ish novel; is in fact longer then any episode will take if you added "what happened previously" or clean action breaks - it would have made it even longer trying to do that.
Not many series' do this though; although making use of multi-episode stories does help a lot if you don't get hung up on holding the viewers hand and taking time to explain previous episodes. Most still use a per-episode arc however - making it ponderous to get through a single story.
Best example in my mind is Hellsing, the original series versus the OVA, it falls down when you need to create tension essentially at an arbitrary point in a story when an episode ends! Versus this example is perhaps Desert Punk, which while it has multi-episode stories, each episode seems to stand well on it's own since it is so darn fast paced.
Anyway, hanging up on the creative semantics and why and why not they are good is silly since most anime is an adaptation of something! Whether it is good or bad is usually up to the creators of the adaptation not what it was adapted off after all - that is, assuming the original was worth adapting in the first place which is always up for debate.
