The rockhopper is a plenty capable bike and plenty of bike for a novice or even an intermediate rider in my opinion. Enjoyment isn't measured by the money you spent on your bike. That being said, it's rather unenjoyable to break parts especially mid-ride and have to improvise or hoof it. The likelihood of breakage depends entirely on your style of riding (smooth or brutal), the type of riding (xc, aggressive xc, fr, dh), and the type of trails and climate of locale.
I believe, as a guy who has been riding for over a decade on bike with mid-grade parts, that chances are you will be fine for years. However I ride in the northeast, have stuck to fireroads and singletrack (until recently), don't do much crashing, and take care of my gear. The things you're likely to go through (and things I went through in 10 years on the same bike) are.... chains, rear cogs, rear derrailleur, and brake pads. The rest is personal preference and the list goes up if you start riding hairy trails or fall a bunch.
And remember, if it's weight you care about, most of us can stand to lose 5 pounds off our body, and doing it would be a lot easier and cheaper than taking it off the bike.
