Having a smarter code completion like the one found in visual assist (or launchy) would be the killer feature.
For example, having these 2 variables:
long + ctrl-space, it should find the second variable, being part one the complete name.
iint + ctrl-space, it should also find the second one, the characters forming iint appearing in this sequence in the first variable (-i-MyLong-I-n-t-Variable)
mvar + ctrl-space, should find both : i-M-yLongInt-V-a-r-iable / f-M-yFloat-V-a-r-iable
mliv + ctrl-space, should also find both, BUT it'd be nice to sort them using a camel case analysis: in iMyLongIntVariable, mliv characters are the upper case letters (part of the camel case "signature"), whereas they are just "normal" letters in the first variable => the second variable should be displayed first.
NB: The last point is an extra step for the feature. =)