Hi All,
This paper is recent and pretty helpful on the ages and apparent history of the SMC and its clusters:
http://arxiv.org/PS_cache/astro-ph/p.../9907398v1.pdf
and provides pretty good evidence regarding the ages of a sample of clusters using HST. They conclude that there have been two distinct bursts of star formation about 2 and 8 gyr ago that formed these extremely massive and rich intermediate age clusters. They are without doubt "globular-like" in structure, mass and size but are different to what one might call a classical G.C ie >10gyr-old, high-mass, extremely rich, extremely low metallicity, RR Lyrae stars, horizontal branch, low turn-off point from the main sequence and strong red-giant and AGB branch etc etc.
There are a larger number of similar clusters to these in the LMC. Our galaxy doesn't have clusters of this sort. The closest Milky Way analogues I can think of off-hand is M67, NGC 188 and NGC 2477, NGC 2158 that are all massive, rich (relatively) old open clusters of intermediate metallicity -- but they are an order of magnitude smaller than what we see in the SMC and particularly the LMC where they are truly "globular-scale" ie >10,000 stars up to 50,000 stars and I guess if we all came back in 4-5 gyr and re-analysed many of them that are now 6-9 gyr old, we'd likely happily call them globular clusters because by then their evolution would have produced the features that define a classical GC (except for metallicity perhaps).
By this definition only NGC 121 passes the grade, but in the end I guess it now depends on what your definition of a G.C is.
I'll continue to have a poke around as time allows.
Best,
Les D