It would be interesting to know what sort of innovations you were looking into.
I've seen a number of people on here modifying the Quest interface in various ways, and it seems that it's possible to edit the appearance of almost any aspect of a game. Some of them look really good, and enhance the player's immersion and enjoyment. As you say, though, a simple interface does the job well enough, as long as the text itself is good.
I think it's encouraging to see someone say that good writing is the most important feature of interactive fiction - it's very easy for me, at least, to get distracted by other things, and forget that the writing itself should probably be my main focus. As an aside, one thing I've noticed from reading various forums is that writers/players of interactive fiction often seem to fall into two categories - those who prefer the 'interactive' aspect, and like challenging games that are primarily driven by logic problems and puzzles, and those who prefer the 'fiction' aspect, and like immersive games that are driven by the characters and plot, with puzzles having less of an emphasis. As a player, I tend to prefer games to tell a story, rather than be what essentially amounts to a book of riddles, and in this case, the quality of the descriptions and writing in general definitely seems to be an important thing.
On the other hand, in a game that is primarily puzzle-driven, or driven by other gameplay mechanics (e.g. hunger/thirst in survival games), I'd possibly argue that the quality and complexity of these puzzles or mechanics is more important than the actual literary quality of the writing itself.