Violinists, cellists, etc.
See, pianists have idiosyncracies, and there are certain sounds and expressions which are just more CONVENIENT to produce at the piano.
Listening to other instruments we don't hear the same things, because of the physically different nature of the instrument, and it's interesting to take influence from them.
Also, I feel listening to MIDIs does alot to tell us what a piece could sound like with no physical barriers.
Some composers composed with the effect of piano writing completyely in mind, and some didn't, and didn't count on pianists applying their instrumental habits on the music.
Of course the habits can be beautiful, but they shouldn't just be there for the sake of a habit 
Hmm... surprisingly safe post from opus12. Where do you stand on the matter? All you tell us is, "it's interesting to take influence from [other instruments.]" It's more than interesting: it's the entire history of modern piano technique, and probably ancient technique as well.
We wouldn't be anywhere if Liszt hadn't heard Paganini, and realized the worlds that were possible on the piano. But he didn't simply transcribe Paganini figurations to a piano setting, he explored the entire range of diverse sounds Paganini was able to create, and applied them to his own instrument. Not only that, he was inspired by Paganini's own imitations of other instruments, and wrote those into his scores (quasi corno; quasi flauto; etc.)
He took Paganini multiple steps further, especially with works like Totentanz, which with its percussive effects and almost bizarre voicing takes piano sonority into the twentieth century - all based on imagining another sound.
Even Bartok, who wanted to imitate the vast repertoire of folk-singer ornaments and "out of tune" sound onto the piano, where the pitches are fixed (unlike violin, which can incorporate any number of slides or ornamental effects), was able to transpose those sounds, through an ingenious pedal technique and unique ornamentation.
Practically every composer whose music we play has a sound that can be paralleled in other instruments, and while the rage for orchestrating piano pieces has safely passed, it is still rather fun to do in programs like Sibelius or Finale.
Walter Ramsey