As it stands, Guido van Rossum has suggested that lambda forms will disappear in ["Python3.0"]. This started a number of threads on comp.lang.python suggesting alternate syntaxes for lambda in the hopes that one of them might be more amenable to GvR's tastes. This pages summarizes these suggestions:
Current Syntax
New Syntaxes
Args Before Expression
Nick Coghlan: def-to syntax #a 1
Nick Coghlan: def-arrow syntax #a 1
Alex Martelli: def-as syntax #b 2
Dave Benjamin: fun syntax #g 7
Roman Suzi: quote-colon syntax #i 9
Expression Before Args
Nick Coghlan: for syntax #f 6
Robert Brewer: for (no-parens) syntax #c 3
Nick Coghlan: def-from syntax #d 4
Nick Coghlan: from syntax (posted to clp, no reference handy)
Michael Spencer: from-args syntax #e 5
Michael Spencer: for-args syntax #e 5
Bengt Richter: colon-function-application syntax #h 8
Real Closures
Real closures subsume the functionality of lambda plus allow for multi-line statements.
Curly braces for single-line and anonymous def for multi-line (from #h 10, boo #h 11, and this is also very similar to how Ruby does it):
References
Anchor(a) [1] http://mail.python.org/pipermail/python-list/2004-December/256859.html
Anchor(b) [2] http://mail.python.org/pipermail/python-list/2004-December/256881.html
Anchor(c) [3] http://mail.python.org/pipermail/python-list/2004-December/257023.html
Anchor(d) [4] http://boredomandlaziness.skystorm.net/2004/12/anonymous-functions-in-python.html
Anchor(e) [5] http://mail.python.org/pipermail/python-list/2004-December/257893.html
Anchor(f) [6] http://mail.python.org/pipermail/python-list/2004-December/257977.html
Anchor(g) [7] http://mail.python.org/pipermail/python-list/2005-January/258441.html
Anchor(h) [8] http://mail.python.org/pipermail/python-list/2005-January/258578.html
Anchor(i) [9] http://mail.python.org/pipermail/python-list/2005-January/258581.html
Anchor(i) [10] http://mail.python.org/pipermail/python-list/2005-January/258113.html