A relatively recent trend in short-term wine storage are cute holders that use the neck of the bottle as the holding point and counter-balance themselves against the weight of the lower portion of the bottle. Some hobbyists have even taken to crafting racks like this themselves (not unlike riddling racks). One well-built example (borrowed from Reddit user “ILovePooch”) is shown here:
This is a nice design, very attractive, with a wide base that should prevent any tipping of the rack, and good points on the top that can be wall-anchored. However, there are concerns about using this for long-term bottle aging.
The short explanation: This is a bad idea for long-term storage. The fundamental reason for this are inherent flaws in the glass that may propagate in high-stress regions (i.e. in the neck and shoulder, in this case) when exposed to wine.
The long explanation: The fracture mechanics of glass are dominated by largest flaw in a stressed region...this is why scoring and breaking works on glass and ceramics, but not on metals. In materials science, we quantify this by calculating a Weibull modulus by testing many hundreds of test specimens. In general, a single pore or surface scratch will not be enough to allow a relatively thick bottle to fracture under a constant minor load. Hence, this design is OK for the short term.
Over time, though, a small (read: tens of microns/< 0.001 inches) crack exposed to an aqueous environment - especially an acidic environment - will grow. The mechanism for this is still debated, but it is usually thought that the atoms at a sharp crack tip in a ceramic tend to react quickly with the water. This makes sense to some extent; the atoms at the crack tip are in a state of triaxial tension when the crack is under a tensile load, meaning they are "higher energy" and more likely to react. Over months, large starting cracks could propagate quickly and cause failure of the bottle. Over years, even small flaws could react with the aqueous environment.
The worst part is that this is not a sure thing. It is a purely statistical process. It may happen to thin-walled bottles, thick-walled bottles, expensive bottles, or bottles of two-buck-chuck. It may never happen if one happens to buy bottles without significant flaws facing the wine (as external (air-facing) and internal cracks in a ceramic are very unlikely to grow under a constant applied stress). For long-term cellaring, it really will be playing the odds.
Freely available further reading: Cicotti, M., “Stress-corrosion mechanisms in silicate glasses,” http://arxiv.org/abs/0901.2809