Any car will have its set of problems. Look at Ford for example in 93, 94 and 95 they put the same engine in their mustangs, thunderbird, tauras's and cougars. All of these engines blew headgaskets aroung or after 100k miles. Mustangs and Tbirds have been around since the 60's maybe even later than that.
Im not going to say to buy one or not to buy one. Just be aware that the subaru wrx isnt the only car in the world that is having problems. Remember most manufacturers buy parts from the lowest bidder which may or may not cause problems. In the case of the WRX the synchros may not have been as good as they expected and the clutch may not be as good as expected amongst many other parts. When a large number of WRX's start having the same problem they will probably recall those parts but until then if you have to pay for ANYTHING on your car be sure to save your reciept. Because if they recall something later on and you already replaced it they HAVE to issue a refund.
You also have to take into consideration that this car and every car contains thousands of moving parts I dont think it would be possible to ever manufacture something with that many parts, especially mass produce it, that would work perfectly the first time everytime.
I think every model and year of every car ever manufactured has gone through at least a half a dozen recalls before the car actually operates as it was designed.