The \textcite command implemented in footnote-dw does almost what you want if we combine it with Multiply cited reference in footnotes, it doesn't print the year and the positions of the pre- and postnotes are different. Fortunately though, with a bit of help from authoryear.cbx we can implement your desired output.
This is from authoryear.cbx (with a few modifications)
\newbool{cbx:parens}
\newbibmacro*{ay:textcite}{%
\printnames{labelname}%
\setunit{%
\global\booltrue{cbx:parens}%
\addspace\bibopenparen}%
\printdate}
\newbibmacro*{ay:textcite:postnote}{%
\iffieldundef{postnote}
{\ifbool{cbx:parens}
{\bibcloseparen}
{}}
{\ifbool{cbx:parens}
{\setunit{\postnotedelim}}
{\setunit{\addspace\bibopenparen}}%
\printfield{postnote}\bibcloseparen}}
Then
\DeclareCiteCommand{\etextcite}[\footnotecheck\cbx@textcite\superfootcite]
{\usebibmacro{prenote}%
\gdef\cbx@savedkeys{}}
{\usebibmacro{ay:textcite}%
\ifciteseen
{\global\boolfalse{cbx:textcitefull}}
{\global\booltrue{cbx:textcitefull}}%
\xappto\cbx@savedkeys{\thefield{entrykey},}}
{\multinamedelim}
{\usebibmacro{ay:textcite:postnote}%
\protected@xappto\cbx@savedcites{{\cbx@savedkeys}}}
is a modification of \textcite in footnote-dw.cbx.
Finally, we need Audrey's \superfullcite from Multiply cited reference in footnotes.
MWE
\documentclass{article}
\usepackage[backend=biber,style=footnote-dw]{biblatex}
\addbibresource{biblatex-examples.bib}
\newbool{cbx:parens}
\newbibmacro*{ay:textcite}{%
\printnames{labelname}%
\setunit{%
\global\booltrue{cbx:parens}%
\addspace\bibopenparen}%
\printdate}
\newbibmacro*{ay:textcite:postnote}{%
\iffieldundef{postnote}
{\ifbool{cbx:parens}
{\bibcloseparen}
{}}
{\ifbool{cbx:parens}
{\setunit{\postnotedelim}}
{\setunit{\addspace\bibopenparen}}%
\printfield{postnote}\bibcloseparen}}
\makeatletter
\DeclareCiteCommand{\etextcite}[\footnotecheck\cbx@textcite\superfootcite]
{\usebibmacro{prenote}%
\gdef\cbx@savedkeys{}}
{\usebibmacro{ay:textcite}%
\ifciteseen
{\global\boolfalse{cbx:textcitefull}}
{\global\booltrue{cbx:textcitefull}}%
\xappto\cbx@savedkeys{\thefield{entrykey},}}
{\multinamedelim}
{\usebibmacro{ay:textcite:postnote}%
\protected@xappto\cbx@savedcites{{\cbx@savedkeys}}}
\DeclareCiteCommand{\superfootcite}[\cbx@wrap]
{\gdef\cbx@keys{}\citetrackerfalse}
{\xappto\cbx@keys{\thefield{entrykey},}}
{}
{\ifcsundef{cbx@lastin@\cbx@keys @\strfield{postnote}}
{\csnumgdef{cbx@lastin@\cbx@keys @\strfield{postnote}}{-1}}{}%
\ifsamepage{\value{instcount}}{\csuse{cbx@lastin@\cbx@keys @\strfield{postnote}}}
{\footnotemark[\csuse{cbx@lastfn@\cbx@keys @\strfield{postnote}}]}
{\xappto\cbx@cite{\noexpand\footcite%
[\thefield{prenote}][\thefield{postnote}]{\cbx@keys}%
\csnumgdef{cbx@lastfn@\cbx@keys @\strfield{postnote}}{\value{\@mpfn}}%
\csnumgdef{cbx@lastin@\cbx@keys @\strfield{postnote}}{\value{instcount}}}}}
\newrobustcmd{\cbx@wrap}[1]{#1\cbx@cite\gdef\cbx@cite{}}
\def\cbx@cite{}
\makeatother
\begin{document}
Lorem \etextcite[cf.][12]{sigfridsson} ipsum \etextcite{geer}
dolor \etextcite{sigfridsson} sit \etextcite{geer} amet \etextcite{wilde}.
\end{document}

\citewith the new\superfootcite. Thebiblatex-dwstyles do all kinds of tracking, so you'll at least have to add\citetrackerfalseto the first (<precode>) argument in the definition of\superfootcite. – Audrey Jul 08 '13 at 14:29biblatex-dwbecause of thefootnote-dw, it can be replaced by any other style, if I can still have references in footnotes. I saw in the post that pages are cited as\superfootcite[<page number>]{<citekey>}. How would tables and figures be cited? – cacamailg Jul 08 '13 at 17:38\cite[<prenote>][<postnote>]{<keys>}. Page references go in<postnote>. So can references to tables or figures. In<prenote>prefixes like "e.g." or "cf." are used.\superfootcitechecks for recurrent\strfield{postnote}+entrykeycombinations. The solution could be extended toprenote. BTW: Use ofxparseisn't necessary for multi-pass citation commands.\textcitein the more recent verbose styles exploits the citation command interface. Under this approach you can access and move trailing punctuation and compress citation labels. – Audrey Jul 08 '13 at 17:55prenotesandpostnotesto be added in the main text rather than in the bibliography itself, like in my MWE. – cacamailg Jul 12 '13 at 03:43prenoteargument in the MWE. The example passes page references toprenotewhen typically they go in thepostnote. Your desired format is unclear, which is why I've been commenting this whole time instead of simply answering. Are you wanting output like:<prenote> <name label> (<year label>, <postnote>)^<footnote mark>? – Audrey Jul 12 '13 at 16:55<prenote>and<postnote>are optional. – cacamailg Jul 12 '13 at 23:33