In The Swimmer, by John Cheever, the plot attempts to disclose the shallowness and emptiness of human relations in everyday upper-class, suburban, and business-minded America.
We are aware that Neddy has a very hard time making true and in-depth connections with nearly everyone. Regardless of naming his swim track after his wife, the fact remains that he has had affairs (namely with Shirley) and even that affair he dubbed as merely for sexual satisfaction.
This makes us wonder: How does his wife feel? Why is she still with him? Does she even know what is going in? Is she as shallow as he is in regards to their relationship? The answer may be that everyone in the story suffers from the same "condition" of shallowness and selfishness that occurs among those who prefer a comfortable life to a meaningful human connection.
This being said, think about the end of the story when he comes home, only to find it empty: This is a clear indication that, in Neddy's heart, there is no lost love for his wife, but he has a HUGE need to return to his lifestyle. He is not mourning her when he sees his house empty; he is simply realizing that he has lost everything.
To answer your question concisely, the answer is "No. Neddy did not really love his wife". Neddy is somewhat incapable of loving anybody. He is way too business-minded, shallow, and selfish to be able to produce anything near love in his heart. Even his insane swimming thing is a way for him to escape everything and everybody. His naming his pool track after his wife is nothing but an attempt to make a connection with her. As we know, it fails as well.