This is an announcement for the paper "Conical square functions in UMD Banach spaces" by Tuomas Hytonen, Jan van Neerven, and Pierre Portal. Abstract: We study conical square function estimates for Banach-valued functions, and introduce a vector-valued analogue of the Coifman-Meyer-Stein tent spaces. Following recent work of Auscher-McIntosh-Russ, the tent spaces in turn are used to construct a scale of vector-valued Hardy spaces associated with a given bisectorial operator \(A\) with certain off-diagonal bounds, such that \(A\) always has a bounded \(H^{\infty}\)-functional calculus on these spaces. This provides a new way of proving functional calculus of \(A\) on the Bochner spaces \(L^p(\R^n;X)\) by checking appropriate conical square function estimates, and also a conical analogue of Bourgain's extension of the Littlewood-Paley theory to the UMD-valued context. Even when \(X=\C\), our approach gives refined \(p\)-dependent versions of known results. Archive classification: math.FA math.SP Mathematics Subject Classification: Primary: 46B09; Secondary: 42B25, 42B35, 46B09, 46E40, 47A60, 47F05 Remarks: 28 pages; submitted for publication The source file(s), tent/newsymbol.sty: 440 bytes tent/tent.bbl: 5616 bytes tent/tent.tex: 91867 bytes, is(are) stored in gzipped form as 0709.1350.tar.gz with size 29kb. The corresponding postcript file has gzipped size 167kb. Submitted from: J.M.A.M.vanNeerven@tudelft.nl The paper may be downloaded from the archive by web browser from URL http://front.math.ucdavis.edu/0709.1350 or http://arXiv.org/abs/0709.1350 or by email in unzipped form by transmitting an empty message with subject line uget 0709.1350 or in gzipped form by using subject line get 0709.1350 to: math@arXiv.org.