While Spore is a good game, I think it would have been even better had EA not forced a release date on Maxis months in advance.
If you go at GameRankings.com, the website offers, at the moment, 27 ratings of SPORE, which come from professional reviewers of 27 other sources (websites + magazines) : none give it a score inferior to 80% (the average being about 86%) !?!
But if you read hundreds of reviews & comments by gamers (on GameSpot, EA/US forum, EA/UK forum), you get a very different picture : a lot of them tell a very different story, denouncing SPORE for being sometimes too childish & simplistic, sometimes too stressing & tedious.
There is a huge contradiction between the evaluation made by professional reviewers and the one made by most gamers (who have probably spent more hours actually playing SPORE with intensity).
My personal bias is that I do not trust the too positive reviews, especially the ones composed by unconditional « fanboys ». When I go on GameSpot, for example, I will only read the reviews written by negative gamers : before buying a game, I want to learn what to expect, in terms of problems, bugs, issues.
At the moment, there is too much negativity surrounding SPORE for me to take the risk of wasting money & time on it.