Re: how does one rekindle his/her interest in tennis?
It will come back. I'm sure everyone at one point or another (sonner or later) loses some interest in the sport. In my case, that happened to me a few years ago and recently towards the end of last year -used to log in to MTF almost everyday and suddenly didn't enter for about a whole month-. Sometimes it is because you're having less free time, other things consuming most of your time or it could be a case of your favourites not doing well enough and you feeling bad about it. This last reason would suck if it's your spot, since it could indicate you're more of a player-fan rather than a tennis supporter.
Either way I'm pretty sure it will come back if it's a sport you really like, and seems like it.