I've heard weirder things, like Goku never kissing Chichi. There will be hugs for Serena and Ash if Serena returns later on.
I was going to address that... I remember a scene during the Cell/Androids saga: when Goku finally got better from his heart disease at Kame House, he holds Chichi/Milk (his wife) and kiss her on a scene that was cut to their feet (and drew a bloody-nose-surprise by Roshi Master/Kame Sennin).
The Serena Kiss Scene make me reminiscent of that very scene, and is one of the reasons I'm sure her kiss to Ash was on the lips.
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On a personal note, I found it very powerful when Serena says "Ash: You're my goal": because she learned that it takes a lot of determination and upbeat attitude like his Pallet Town Ashy Boy to start unknown ventures; on Ash's case, save his beloved Pokémon off a building or a volcano and on Serena's one, gather up courage to confess her feelings before going to unknown waters on her own for her first time.
Taking his League performance jokes aside, I assume Serena said that to make a stand on the fact that it takes to be like Ash to succeed on Performance (and sentimental) grounds.
Even though I am an recent Amourshipper, I must confess I enjoyed the ride a lot (besides it reconnected me with the Anime after I gave up of it when Harrison defeated Ash on Johto)... I'm not sure if I will watch SM, but I will try to contribute to Amour with fanfics or something... Thanks everyone for your thoughts, speculation and even the low expectations.