Contextually speaking, the case for women deacons from 1 Tim. 3:11 is quite weak.
Some argue that since the noun for women/wives (gunaikas) is not articular it cannot be rendered as "likewise, their wives", since, theoretically, the definite article would need to be emplaced for it to retain a possessive sense. That seems to be a rather slim thread to hang your case on, since "likewise, wives..." does not really constitute a difficult read of the passage.
What is much more obvious is that, since the feminine form of 'diakonos' means the act of service itself, and therefore (as in Romans 16:1) the use of this term for women (whether in its broad or narrow sense) will only be found in the masculine form, if there were women in the office of deacon they would be assumed under the masculine title in verse 8, and it would be entirely superfluous to mention them under the title of "women" in verse 11, as opposed to the common understanding of this term as referring to the officer's wives.
On the other hand, what follows in verse 12 plainly shows that those 'gunaikas' in verse 11 are indeed the wives of the deacons. Paul clearly directs the admonition of verse 12 to an all male diaconate, thus ruling out the possibility that women are included under the masculine plural form.
It would seem a little odd, with all of the extensive admonitions to male elders and deacons, that Paul would insert a mere phrase into the midst of this whole discussion regarding females in the diaconate, and then immediately return to an all male discussion. Wait, maybe he was just speaking of one more requirement for the male deacons, and that regarding their wives! Hmmmm....
[Edited on 7-26-2006 by Archlute]
[Edited on 7-26-2006 by Archlute]