I have previously written here about the "poet-critic," the creative writer of poetry or fiction who also takes literary criticism seriously enough to attempt it as well. As I said in that post, in some ways poets and fiction writers are in the best position to discuss what goes into the creation of works of literature in the first place, and a willingness among creative writers to also write serious literary criticism (including book reviews, but going beyond them as well) could only be welcome. (Even if it's Dale Peck.)
However, there has also undeniably always been an uneasy relationship between creative writing and literary criticism, sometimes verging on hostility, and I don't just mean the "snarkiness," as it's now called, that some creative writers justifiably resent vis-a-vis some book reviewers. At one extreme are poets and fiction writers (and some readers) who find criticism an unwanted imposition on works of creative writing, something that only impedes the direct appreciation of poetry or fiction on the part of their ideal readers. In some cases these writers (I've known a few) almost regard criticism as an affront to the practice of their art.
At the other extreme are critics who at least implicitly regard works of literature to be incomplete, untested, until criticism has been able to appropriately classify, dissect, and evaluate them. With some critics (I've known a few of these, as well), especially of the academic variety, works of literature are finally only "cases," grist for the critical and scholarly mills. Academic criticism ultimately became so suffused with this attitude toward literature that now there's barely any pretense to an interest in literature itself. It's finally just a convenient starting-point for advancing other agendas.
Most readers probably are, of course, somewhere between these two extremes in their attitudes toward the proper relationship between literature and literary criticism. Most would likely welcome constructive critical consideration of poetry and fiction, as long as such criticism seemed to acknowledge that ultimately it is the means to greater understanding and appreciation of literature, both in regard to individual books and poems and to a broader perspective about the nature and goals of literature. In my opinion, writers and critics, as well as those who simply consider themselves interested readers, ultimately spring from the same source: a rapt, transforming act of reading. The critic emerges from this experience saying "I want to know how this thing (poem, story, novel) works"; the writer emerges saying "I want to do something like that." What the critic and writer subsequently go on to pursue is divergent from this initial experience, but ideally both can be traced back to the common source.
Perhaps the very abandonment of real literary criticism by academic critics represents an opportunity to rediscover this common source. I've noticed lately that many literary weblogs are indeed trying out more ambitious ways of engaging with current books and writing--longer reviews, shorter but pithier reviews, well-conducted interviews with authors (Robert Birnbaum obviously, but Mark Sarvas's interview with Andrew Sean Greer could also serve as a model of the form), extended commentary of various sorts--but reattaching criticism to literature needn't take place only in blogs. Other kinds of online or print forums in which writing and the engaged appraisal and appreciation of writing were both encouraged would be most apropos. Certainly criticism can't exist at all without a flourishing literary culture of poets and fiction writers. But in the long run I'm not sure that serious poetry and fiction can themselves survive--at least in a wholly healthy form--without interested readers willing to convert their interest into intelligent criticism.