There are more than a dozen new types that are proposed to be added to the input tag. Some of these appear to be far more useful than the others. There is one reason though why even those types which at first glance don't appear all that useful should not be discarded without a closer examination.
When HTML 4 was developed the web ran in web browsers running on desktop computers. These computers all had a keyboard with a full selection of letters, numbers and other symbols all easily available. Now web pages run on all sorts of other devices including mobile phones and tablet computers which do not have a keyboard. Instead these devices have a touch screen and display a partial keyboard on the screen. To cover all of the characters of a normal keyboard generally requires at least two or more different displays that you'd need to switch between to be able to access all the characters found on a keyboard. Some of the new types target this situation specifically. Types such as "email", "tel", and "url" identify the type of input expected for those fields and so the on screen keyboard can be customised to display the characters most commonly expected in that particular type of input - the @ symbol would be more accessible for email addresses and for phone numbers the number keys along with space + ( and ) would be offered - so a phone number such as +61 (0)2 9999 9999 would be able to be entered without needing to switch to display alternative keys on the touch screen.
Adding a list attribute to any input field to attach it to a <datalist> (another new HTML 5 tag) provides you with a combobox. This is the form field type that is most commonly available on other platforms that was missed from the field types available in HTML 4. It is called a combobox of course because it effectively combines two input fields into one with the field containing the equivalent of both a regular input field and a select list. The value can either be selected from the list or if the required value isn't in the list it can be typed in. This is very useful where there is a small range of very common values for the field to have as well as a large number of not so common values. Hopefully the addition of a true combobox field will eventually do away with those amateur web page writers incorrectly referring to the select list as a combobox. A select list is only half of a combobox.
Similarly type="color" will produce a colour wheel allowing colours to be picked more easily, type="number" will create a spinner tool and type="range" will produce a slider. While these are perhaps not needed quite as often the addition of these form field types expands the options available for creating consistent forms and so these types are definitely a useful addition.
The other new types are probably less useful than the ones already discussed but with most of them the new controls that they will add will at least be useful in those instances where you need to collect that type of data and they certainly do no great harm having them there as people are unlikely to misuse any of them as they each will restrict the possible input to that which corresponds to their type.
The only new type that serves no purpose that I have yet been able to discover is type="search". This is the only one that I can see that could potentially be misused since it seems to have nothing to distinguish it from a regular type="text" field (particularly in a form where the only other field is a submit button and the form uses method="get" as that combination effectively defines a search form).
This article written by Stephen Chapman, Felgall Pty Ltd.