I am a believer in "branding" non-com extensions as a way to generate interest in a particular ccTLD or in this case ggTLD (GeoGraphical TLD).
Problem with .EU is that to everyone outside Europe it really means "nothing". It sounds like "eeeewww", which is not a good way to go from a marketing perspective. This is a double "whammy" against the ggTLD in my opinion
THEREFORE, if you were to buy these names for speculative purposes only go for generics that Europeans would buy. Since American's apparently can't speculate on this domain, my guess is you won't even get tepid interest on Domain Forums located here in North America. So you would have to peddle these things on European Domain Forums which will limit the scope of your buying population, THUS lowering price. Another thing you have to take into consideration is that MORE tlds on on their way. This isn't necessarily bad news for ccTLDs/ggTLDs but isn't good news either. Especially given our "global economy" appetite.
If you are going to speculate in this environment, the domains you should buy need to have "liquidity" to them. Meaning you should be able to "flip" them the next day after buying. This is a change from an earlier position I once took. I used to think that buying today, to sell down the road until the "domain" catches interest was a good way to go. NOT... I think a more prudent way to speculate is to give the domain/TLD a "liquidity" test: If you think you could sell it the next day for more, then buy. If you are "not sure", skip it!!! (NOTE: This is advice for the speculator----not for developers ---which for developers would be to go with the "brandable" extension and stick with it---don't be so worried about liquidity, as much as the "marketability" of the domain)
The only reason why .US has worked out for speculators is that apparently anyone can buy them AND their is some interest in the market for them here in the states. Time will tell, but certainly you cannot go wrong here with Generic Dot US names. Unfortunately, I was late to this market and don't have a lot.
HERE is my "Domain Investment" strategy:
Right now I am "shorting" US, and opting for .ws and .St at reg fees. On the gTLD side, I am going with "true".org names (i.e
www.USTennis.org). I am neutral on .biz right now, and will only buy true generics. With .info's the names HAVE to be very "niche" oriented. They don't have to be as "generic" to be "good". I haven't totally given up on .com's, but unless I win the lottery and could get some quality "type-in" names, I don't really have the patience for average .com domains---in other words: "Been there, don't that".
edit: Almost forgot about dot com's ugly step child: .net
I don't really have an opinion either way on .net other than to say Coffee.net is about the best name .net out there and if Bob ever wants to sell it I may try to go after it. I do have (1) net though--- Cuba-Travel.net (whoohoo!!)
