You may define your own enumeration list using enumerate and (re)storing the counter:
\documentclass{beamer}
\makeatletter
\newenvironment{cenumerate}{%
\enumerate
\setcounter{\@enumctr}{\csname saved@\@enumctr\endcsname}%
}{%
\expandafter\xdef\csname saved@\@enumctr\endcsname{\the\value{\@enumctr}}%
\endenumerate
}
\newenvironment{cenumerate*}{%
\enumerate
}{%
\expandafter\xdef\csname saved@\@enumctr\endcsname{\the\value{\@enumctr}}%
\endenumerate
}
\makeatother
\begin{document}
\begin{frame}
\begin{cenumerate*}% starting a new continous enumerate
\item 1st
\item 2nd
\item 3rd
\item 4th
\end{cenumerate*}
\end{frame}
\begin{frame}
\begin{cenumerate}
\item 5th
\item 6th
\item 7th
\item 8th
\end{cenumerate}
\end{frame}
\begin{frame}
\begin{cenumerate}
\item 9th
\item 10th
\item 11th
\item 12th
\end{cenumerate}
\end{frame}
\end{document}
But this would fail, if you use step by step enumerations like:
\begin{frame}
\begin{cenumerate}
\item 5th
\item<2-4> 6th
\item<3-4> 7th
\item<4> 8th
\end{cenumerate}
\end{frame}
\framebreakto add manual frame breaks. This would top align the partial list before the frame break. – Schweinebacke Dec 14 '11 at 06:39\begin{frame}[allowframebreaks=0.7,t]if you want it at 70% of the page – Dec 14 '11 at 07:40