I have a test program that basically pushed ints to a vector, and I'm getting 
this output:

~"11\t    v.push_back(10);\n"
*stopped,frame={addr="0x08048681",func="main",args=[],file="a.cpp",fullname="/tmp/a.cpp",line="11"},thread-id="1",stopped-threads="all"
(gdb)
-var-create V * v
^done,name="V",numchild="0",value="std::vector of length 0, capacity 
0",type="std::vector<int, std::allocator<int> > &",thread-id="1"
(gdb)
-var-list-children V
^done,numchild="0",displayhint="array"
(gdb)
-exec-next
^running
*running,thread-id="all"
(gdb)
*stopped,reason="end-stepping-range",frame={addr="0x0804869a",func="main",args=[],file="a.cpp",fullname="/tmp/a.cpp",line="12"},thread-id="1",stopped-threads="all"
(gdb)
-var-update V
^done,changelist=[{name="V",in_scope="true",type_changed="false",displayhint="array",children=[{name="V.
[0]",exp="[0]",numchild="0",type="int",thread-id="1"}]}]
(gdb)
-var-evaluate-expression V.[0]
^done,value="10"
(gdb)
-var-info-path-expression V.[0]
^done,path_expr="((std::_Vector_base<int, std::allocator<int> >) v)"
(gdb)

I don't know what the right output from the last command might be, and whether 
it's possible to produce the right output, but saying that expression for the 
first element is 'v' is just bogus. I imagine we want to fix this by 7.0