another problem is certification of games, of course not all sellers demend that j2me game must be signed but in future probably it will cheange, certification mean that it prove that your j2me game is safe, BUT you have to make cert FOR EVERY PHONE!!! yes read about it, it costs a couple of dolars but it will be not good for industry, becouse only big companys will have money to pay certifications for all phones, the most funny thing is that f: they treat for example sonyericsson k500 and f500 as two diffrent phones 
but they specifications of them are THE SAME, but you have to pay for them all…
On the other hand i think that in the market is place for both: java and symbian games, as long as people buy them . If they have good game they will just but it no matter in what language it was made, Also symbian devices are not all the same as you could think… and also symbian is not easiest to program as java. Of course testing it is true that the game must be tested on as much devices as possible but it is not the foult of java but the very bad imlpementation of phone vendors ,for example in old simens pones drawing images using standard graphics context was very slow, but on the same device drawing images using specific simens java api was really fast… well no pain no game…
and j2me future , think it will not be so bad, for mass market phones java is the best, becouse:
- it is industry standard
- it is well known in the market, phones with j2me sell better
- some people do not know what symbian is, also they do not need such system, they demand easy to use phone with games (and here j2me has its place)
- there are probably thousends of shops that sell j2me games, and not all sell symbian games, i know the biggest like handago yes, but that smaller no
remember also that j2me industry goes much faster that you could think, three years ago nobody would imagine that we will have 3d in phones and what now, we have m3g or mascot capsule, and what next http://www.jcp.org/en/jsr/detail?id=239 opengl es implementation for java, accelerated games like w900 (which do not have symbian). So the situation is not very bad, also phone manufactures make better j2me implenetataion becouse buyers demand good quality, so new phones are good for programming j2me games, the problem is with that older ones which are the majority in the market, but slowly people will move to new phones (typical lifecycle of a phone is short generally) which for us is better
symbian games of course will take much more role in future becouse they are faster, look better etc etc and also will be safe becouse of certification (but how much wil it cost i do not know), how phone manufactures see the future of mobile gaming? take a look on this gdc session:
http://www.gdctv.net/basic/index.htm#nokia - on the bootom there is session : “The Next Generation of Mobile Gaming - An overview” this material shows what nokia want to make in next two years, especially watch game trailers, they are very intresting, but also this mean that we have to learn symbian, well industry will demand it and users
