Listing alphabetically by author, the five novellas I'm planning to nominate for the Hugo Award are:
Paolo Bacigalupi, The Alchemist
Ted Chiang, The Lifecycle of Software Objects
Paul Park, Ghosts Doing the Orange Dance
Robert Reed, A History of Terraforming
Rachel Swirsky, The Lady Who Plucked Red Flowers Beneath the Queen's Window
"The Alchemist" was very recently published in book form by Subterranean (which also boasts the Chiang and Swirsky stories -- a great showing for that small press in this category), but is eligible for a Hugo this year because it was released on audio by Audible in 2010. The same is true for Tobias Buckell's "The Executioness," set in the same universe, which I also strongly considered nominating. Other near-misses for me were "The Mystery Knight" by George R.R. Martin and "The Sultan of the Clouds" by Geoffrey A. Landis.
All of my choices except the Robert Reed piece are current nominees for the Nebula Award. My tastes don't usually align so well with the Nebula voters, and you will see much less overlap in the other categories.