Enough students to be noticeable pronounce island as ‘ice-land’, ‘eyes-land’ or ‘is-land’. Yes, an island is land, but that’s not relevant. There never was an /s/ in the pronunciation of island – the Middle English was iland and the Old English was igland. In fact, īeg meant ‘island’, so an island is really an island-land. Then someone added the s by analogy with the unrelated isle, from Latin insula via Old French.
Iceland is an island, and what prompted this post was finding out that the Icelandic word for Iceland is Ísland, which I did not know from a childhood hobby of stamp collecting. (I can’t remember that I actually had any stamps from Iceland.) In a post on the Lingua Franca blog, William Germano mentioned that Háskóli Íslands is not ‘the Haskoli Islands’, but ‘the University of Iceland‘. Thinking about it, I guessed that Háskóli is ha (high) + skoli (school), which Wiktionary confirms, and which actually makes more sense than the Latinate university, which means approximately ‘one community (of scholars)’. According to Wikipedia, the Icelandic word for ‘high school’ is framhaldsskóli (‘continued school’). (He also ponders adopting the Icelandic name Bjór Garðurinn, which means ‘beer garden’. The Germanic-ness of that is clear.)
Ireland is also an island, and in my non-rhotic pronunciation those two are pronounced identically. I sometimes find myself introducing a small /r/ to emphasise the difference.
The spelling island took off in the 1750s, for reasons I can’t discover – it was too late for the ‘Age of Discovery’ and too early for James Cook. The spelling iland was used as late as the 1788 – one online source of the diary of a First Fleet officer gave ‘Lord Howe Hand’. When I checked with the scan of the original, I found that it was actually Iland with a curlicue on the I, which the OCR had read as Hand.